Fuel Guage not working
05-03-2006, 09:18 AM
#11
Guest
Posts: n/a
Re: Fuel Guage not working
The unit should cost under a hundred, you are either being quoted for
the wrong part or are getting ripped off.
Here is a good diagnostic page for your gauges:
http://www.monsterslayer.com/jeep/Gauges.htm
If I remember right, the ground for the sender is just a black wire
screwed into the frame. They get ratty and fail.
I recommend soaking all the tank bolts and nuts with penetrating oil for
several days before starting the job.
Tank size.... Hmmm I 'think' it is mostly a depth difference in the
tanks. I think the small tank has a square back and the larger one is
cut on a 30 deg angle for the Jeeps departure angle so the tank doesn't
tag the ground.
Supposedly I have a YJ skid plate here. It measures 5 1/2" below the
rear cross member. The 20 gallon tank measures 8 1/2" below the cross
member.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)
Joe and Joann wrote:
>
> I have a 90 YJ Sahara 4.2 L with about 70K miles. The fuel guage just
> stopped working. It always reads zero or almost zero.The rest of the
> guages working OK. My guess is the sending unit. Any other likely
> possibilities. The dealer wanted nearly $250 for A new sender (not
> including installation) This seems a bit high to me, more like the price
> for the FI unit that includes the pump. Is there anyway to isolate the
> problem to the guage itself rather than the sender. If it is important,
> the guage does move slightly to the right when the power is turned on,
> but only gets to empty.
>
> So assuming it is the sender and I can find one, any tips on dropping
> the tank. Also is there any way to tell the difference between the 14.5
> gallon tank and the 20. Pretty sure I have the smaller tank, but I never
> let it get very low, so I am not sure.
>
> Aloha from Maui
> Joe
the wrong part or are getting ripped off.
Here is a good diagnostic page for your gauges:
http://www.monsterslayer.com/jeep/Gauges.htm
If I remember right, the ground for the sender is just a black wire
screwed into the frame. They get ratty and fail.
I recommend soaking all the tank bolts and nuts with penetrating oil for
several days before starting the job.
Tank size.... Hmmm I 'think' it is mostly a depth difference in the
tanks. I think the small tank has a square back and the larger one is
cut on a 30 deg angle for the Jeeps departure angle so the tank doesn't
tag the ground.
Supposedly I have a YJ skid plate here. It measures 5 1/2" below the
rear cross member. The 20 gallon tank measures 8 1/2" below the cross
member.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)
Joe and Joann wrote:
>
> I have a 90 YJ Sahara 4.2 L with about 70K miles. The fuel guage just
> stopped working. It always reads zero or almost zero.The rest of the
> guages working OK. My guess is the sending unit. Any other likely
> possibilities. The dealer wanted nearly $250 for A new sender (not
> including installation) This seems a bit high to me, more like the price
> for the FI unit that includes the pump. Is there anyway to isolate the
> problem to the guage itself rather than the sender. If it is important,
> the guage does move slightly to the right when the power is turned on,
> but only gets to empty.
>
> So assuming it is the sender and I can find one, any tips on dropping
> the tank. Also is there any way to tell the difference between the 14.5
> gallon tank and the 20. Pretty sure I have the smaller tank, but I never
> let it get very low, so I am not sure.
>
> Aloha from Maui
> Joe
05-03-2006, 09:18 AM
#12
Guest
Posts: n/a
Re: Fuel Guage not working
The unit should cost under a hundred, you are either being quoted for
the wrong part or are getting ripped off.
Here is a good diagnostic page for your gauges:
http://www.monsterslayer.com/jeep/Gauges.htm
If I remember right, the ground for the sender is just a black wire
screwed into the frame. They get ratty and fail.
I recommend soaking all the tank bolts and nuts with penetrating oil for
several days before starting the job.
Tank size.... Hmmm I 'think' it is mostly a depth difference in the
tanks. I think the small tank has a square back and the larger one is
cut on a 30 deg angle for the Jeeps departure angle so the tank doesn't
tag the ground.
Supposedly I have a YJ skid plate here. It measures 5 1/2" below the
rear cross member. The 20 gallon tank measures 8 1/2" below the cross
member.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)
Joe and Joann wrote:
>
> I have a 90 YJ Sahara 4.2 L with about 70K miles. The fuel guage just
> stopped working. It always reads zero or almost zero.The rest of the
> guages working OK. My guess is the sending unit. Any other likely
> possibilities. The dealer wanted nearly $250 for A new sender (not
> including installation) This seems a bit high to me, more like the price
> for the FI unit that includes the pump. Is there anyway to isolate the
> problem to the guage itself rather than the sender. If it is important,
> the guage does move slightly to the right when the power is turned on,
> but only gets to empty.
>
> So assuming it is the sender and I can find one, any tips on dropping
> the tank. Also is there any way to tell the difference between the 14.5
> gallon tank and the 20. Pretty sure I have the smaller tank, but I never
> let it get very low, so I am not sure.
>
> Aloha from Maui
> Joe
the wrong part or are getting ripped off.
Here is a good diagnostic page for your gauges:
http://www.monsterslayer.com/jeep/Gauges.htm
If I remember right, the ground for the sender is just a black wire
screwed into the frame. They get ratty and fail.
I recommend soaking all the tank bolts and nuts with penetrating oil for
several days before starting the job.
Tank size.... Hmmm I 'think' it is mostly a depth difference in the
tanks. I think the small tank has a square back and the larger one is
cut on a 30 deg angle for the Jeeps departure angle so the tank doesn't
tag the ground.
Supposedly I have a YJ skid plate here. It measures 5 1/2" below the
rear cross member. The 20 gallon tank measures 8 1/2" below the cross
member.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)
Joe and Joann wrote:
>
> I have a 90 YJ Sahara 4.2 L with about 70K miles. The fuel guage just
> stopped working. It always reads zero or almost zero.The rest of the
> guages working OK. My guess is the sending unit. Any other likely
> possibilities. The dealer wanted nearly $250 for A new sender (not
> including installation) This seems a bit high to me, more like the price
> for the FI unit that includes the pump. Is there anyway to isolate the
> problem to the guage itself rather than the sender. If it is important,
> the guage does move slightly to the right when the power is turned on,
> but only gets to empty.
>
> So assuming it is the sender and I can find one, any tips on dropping
> the tank. Also is there any way to tell the difference between the 14.5
> gallon tank and the 20. Pretty sure I have the smaller tank, but I never
> let it get very low, so I am not sure.
>
> Aloha from Maui
> Joe
05-03-2006, 09:18 AM
#13
Guest
Posts: n/a
Re: Fuel Guage not working
The unit should cost under a hundred, you are either being quoted for
the wrong part or are getting ripped off.
Here is a good diagnostic page for your gauges:
http://www.monsterslayer.com/jeep/Gauges.htm
If I remember right, the ground for the sender is just a black wire
screwed into the frame. They get ratty and fail.
I recommend soaking all the tank bolts and nuts with penetrating oil for
several days before starting the job.
Tank size.... Hmmm I 'think' it is mostly a depth difference in the
tanks. I think the small tank has a square back and the larger one is
cut on a 30 deg angle for the Jeeps departure angle so the tank doesn't
tag the ground.
Supposedly I have a YJ skid plate here. It measures 5 1/2" below the
rear cross member. The 20 gallon tank measures 8 1/2" below the cross
member.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)
Joe and Joann wrote:
>
> I have a 90 YJ Sahara 4.2 L with about 70K miles. The fuel guage just
> stopped working. It always reads zero or almost zero.The rest of the
> guages working OK. My guess is the sending unit. Any other likely
> possibilities. The dealer wanted nearly $250 for A new sender (not
> including installation) This seems a bit high to me, more like the price
> for the FI unit that includes the pump. Is there anyway to isolate the
> problem to the guage itself rather than the sender. If it is important,
> the guage does move slightly to the right when the power is turned on,
> but only gets to empty.
>
> So assuming it is the sender and I can find one, any tips on dropping
> the tank. Also is there any way to tell the difference between the 14.5
> gallon tank and the 20. Pretty sure I have the smaller tank, but I never
> let it get very low, so I am not sure.
>
> Aloha from Maui
> Joe
the wrong part or are getting ripped off.
Here is a good diagnostic page for your gauges:
http://www.monsterslayer.com/jeep/Gauges.htm
If I remember right, the ground for the sender is just a black wire
screwed into the frame. They get ratty and fail.
I recommend soaking all the tank bolts and nuts with penetrating oil for
several days before starting the job.
Tank size.... Hmmm I 'think' it is mostly a depth difference in the
tanks. I think the small tank has a square back and the larger one is
cut on a 30 deg angle for the Jeeps departure angle so the tank doesn't
tag the ground.
Supposedly I have a YJ skid plate here. It measures 5 1/2" below the
rear cross member. The 20 gallon tank measures 8 1/2" below the cross
member.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)
Joe and Joann wrote:
>
> I have a 90 YJ Sahara 4.2 L with about 70K miles. The fuel guage just
> stopped working. It always reads zero or almost zero.The rest of the
> guages working OK. My guess is the sending unit. Any other likely
> possibilities. The dealer wanted nearly $250 for A new sender (not
> including installation) This seems a bit high to me, more like the price
> for the FI unit that includes the pump. Is there anyway to isolate the
> problem to the guage itself rather than the sender. If it is important,
> the guage does move slightly to the right when the power is turned on,
> but only gets to empty.
>
> So assuming it is the sender and I can find one, any tips on dropping
> the tank. Also is there any way to tell the difference between the 14.5
> gallon tank and the 20. Pretty sure I have the smaller tank, but I never
> let it get very low, so I am not sure.
>
> Aloha from Maui
> Joe
05-03-2006, 11:06 AM
#14
Guest
Posts: n/a
Re: Fuel Guage not working
Sorry, but this Haynes manual is terrible. That range of model years had a
number of significant changes, and the manual doesn't even discuss the
possibility of a fuel tank without an electric fuel pump in it.
If you have a saturated float, sometimes they can be repaired. If you have
another vehicle, it would be good to identify for sure which part is busted,
before spending $250 on a sender.
Earle
"Joe and Joann" <mauijoeb@removehawaii.rr.com> wrote in message
news:NfX5g.11379$MP2.1027@tornado.socal.rr.com...
> Thanks Earl
> Since I have the carb 4.2 L with the mechanical pump, I sure don't need
> the in the tank pump used on the FI model. Hard to believe that price
> isn't for the combined pump/sender unit as you said. Thanks again for
> the ideas.
>
>
> Earle Horton wrote:
> > The sender unit consists of a float attached to a moveable arm, that
moves a
> > variable resistor. The electrical resistance at the sender unit
terminals
> > will change as the arm is moved. I can tell you right now, that the
Haynes
> > Automotive Repair Manual that I have, part number 50030 (1777), for the
1987
> > through 1995 Jeep Wrangler, does not contain the resistance values, that
you
> > need to test the sender unit. :o( A cursory scan of that section of the
> > manual indicates, that it may be useful for removing the tank. I
suggest
> > removing the tank, to inspect the sender unit. :o(
> >
> > The sender unit is tested electrically, by moving the arm with a DVOM
(Drive
> > Vehicle Off Mountain or Digital Volt Ohm Meter, I can't remember which)
> > attached to the sender unit terminals. The resistance should change
> > smoothly as the arm is moved. Lacking the specifications, I can't tell
you
> > more. If the float is saturated or full of fuel, it will feel heavy or
make
> > a sloshing sound.
> >
> > Other suspects are a faulty electrical connection at the fuel
pump/sender
> > unit connector, a fault in the wiring to the sender unit, and a bad
gauge.
> > If you can identify and access the wires to the sender unit (Haynes
wiring
> > diagrams are pretty bad too) then you can check for voltage to the
sender
> > unit with the key on. We used to short the terminal to ground, and
watch
> > the gauge go to full, on some older vehicles, but I do not know whether
this
> > is recommended for your vehicle. The Haynes manual is short on
> > troubleshooting tips in this area.
> >
> > It does sound as if the price quoted, is for a sender/fuel pump unit.
They
> > appear to be a single unit. On vehicles with a 20 gallon tank, the fuel
> > pump/sender unit is mounted with eight screws. The fifteen gallon tank
has
> > a lock ring. The Haynes manual says "if the ring is difficult to
remove,
> > tap it loose with a wood dowel or brass punch and a small mallet (DO NOT
use
> > a steel punch, or you could cause an explosion!)" They show a steel
> > screwdriver being used.
> >
> > The behavior of your gauge is consistent with a flooded float, but not a
> > 100% indication. On my old Plymouth Valiant, this was a fifteen minute
job,
> > if the tank was below one quarter full. Things sure have changed. My
> > advice is to get some penetrating oil on the tank mounting bolts, a
couple
> > of days before you try dropping the tank.
> >
> > Earle
> >
> > "Joe and Joann" <mauijoeb@removehawaii.rr.com> wrote in message
> > news:EKV5g.11377$MP2.1636@tornado.socal.rr.com...
> >> I have a 90 YJ Sahara 4.2 L with about 70K miles. The fuel guage just
> >> stopped working. It always reads zero or almost zero.The rest of the
> >> guages working OK. My guess is the sending unit. Any other likely
> >> possibilities. The dealer wanted nearly $250 for A new sender (not
> >> including installation) This seems a bit high to me, more like the
price
> >> for the FI unit that includes the pump. Is there anyway to isolate the
> >> problem to the guage itself rather than the sender. If it is important,
> >> the guage does move slightly to the right when the power is turned on,
> >> but only gets to empty.
> >>
> >> So assuming it is the sender and I can find one, any tips on dropping
> >> the tank. Also is there any way to tell the difference between the 14.5
> >> gallon tank and the 20. Pretty sure I have the smaller tank, but I
never
> >> let it get very low, so I am not sure.
> >>
> >> Aloha from Maui
> >> Joe
> >
> >
number of significant changes, and the manual doesn't even discuss the
possibility of a fuel tank without an electric fuel pump in it.
If you have a saturated float, sometimes they can be repaired. If you have
another vehicle, it would be good to identify for sure which part is busted,
before spending $250 on a sender.
Earle
"Joe and Joann" <mauijoeb@removehawaii.rr.com> wrote in message
news:NfX5g.11379$MP2.1027@tornado.socal.rr.com...
> Thanks Earl
> Since I have the carb 4.2 L with the mechanical pump, I sure don't need
> the in the tank pump used on the FI model. Hard to believe that price
> isn't for the combined pump/sender unit as you said. Thanks again for
> the ideas.
>
>
> Earle Horton wrote:
> > The sender unit consists of a float attached to a moveable arm, that
moves a
> > variable resistor. The electrical resistance at the sender unit
terminals
> > will change as the arm is moved. I can tell you right now, that the
Haynes
> > Automotive Repair Manual that I have, part number 50030 (1777), for the
1987
> > through 1995 Jeep Wrangler, does not contain the resistance values, that
you
> > need to test the sender unit. :o( A cursory scan of that section of the
> > manual indicates, that it may be useful for removing the tank. I
suggest
> > removing the tank, to inspect the sender unit. :o(
> >
> > The sender unit is tested electrically, by moving the arm with a DVOM
(Drive
> > Vehicle Off Mountain or Digital Volt Ohm Meter, I can't remember which)
> > attached to the sender unit terminals. The resistance should change
> > smoothly as the arm is moved. Lacking the specifications, I can't tell
you
> > more. If the float is saturated or full of fuel, it will feel heavy or
make
> > a sloshing sound.
> >
> > Other suspects are a faulty electrical connection at the fuel
pump/sender
> > unit connector, a fault in the wiring to the sender unit, and a bad
gauge.
> > If you can identify and access the wires to the sender unit (Haynes
wiring
> > diagrams are pretty bad too) then you can check for voltage to the
sender
> > unit with the key on. We used to short the terminal to ground, and
watch
> > the gauge go to full, on some older vehicles, but I do not know whether
this
> > is recommended for your vehicle. The Haynes manual is short on
> > troubleshooting tips in this area.
> >
> > It does sound as if the price quoted, is for a sender/fuel pump unit.
They
> > appear to be a single unit. On vehicles with a 20 gallon tank, the fuel
> > pump/sender unit is mounted with eight screws. The fifteen gallon tank
has
> > a lock ring. The Haynes manual says "if the ring is difficult to
remove,
> > tap it loose with a wood dowel or brass punch and a small mallet (DO NOT
use
> > a steel punch, or you could cause an explosion!)" They show a steel
> > screwdriver being used.
> >
> > The behavior of your gauge is consistent with a flooded float, but not a
> > 100% indication. On my old Plymouth Valiant, this was a fifteen minute
job,
> > if the tank was below one quarter full. Things sure have changed. My
> > advice is to get some penetrating oil on the tank mounting bolts, a
couple
> > of days before you try dropping the tank.
> >
> > Earle
> >
> > "Joe and Joann" <mauijoeb@removehawaii.rr.com> wrote in message
> > news:EKV5g.11377$MP2.1636@tornado.socal.rr.com...
> >> I have a 90 YJ Sahara 4.2 L with about 70K miles. The fuel guage just
> >> stopped working. It always reads zero or almost zero.The rest of the
> >> guages working OK. My guess is the sending unit. Any other likely
> >> possibilities. The dealer wanted nearly $250 for A new sender (not
> >> including installation) This seems a bit high to me, more like the
price
> >> for the FI unit that includes the pump. Is there anyway to isolate the
> >> problem to the guage itself rather than the sender. If it is important,
> >> the guage does move slightly to the right when the power is turned on,
> >> but only gets to empty.
> >>
> >> So assuming it is the sender and I can find one, any tips on dropping
> >> the tank. Also is there any way to tell the difference between the 14.5
> >> gallon tank and the 20. Pretty sure I have the smaller tank, but I
never
> >> let it get very low, so I am not sure.
> >>
> >> Aloha from Maui
> >> Joe
> >
> >
05-03-2006, 11:06 AM
#15
Guest
Posts: n/a
Re: Fuel Guage not working
Sorry, but this Haynes manual is terrible. That range of model years had a
number of significant changes, and the manual doesn't even discuss the
possibility of a fuel tank without an electric fuel pump in it.
If you have a saturated float, sometimes they can be repaired. If you have
another vehicle, it would be good to identify for sure which part is busted,
before spending $250 on a sender.
Earle
"Joe and Joann" <mauijoeb@removehawaii.rr.com> wrote in message
news:NfX5g.11379$MP2.1027@tornado.socal.rr.com...
> Thanks Earl
> Since I have the carb 4.2 L with the mechanical pump, I sure don't need
> the in the tank pump used on the FI model. Hard to believe that price
> isn't for the combined pump/sender unit as you said. Thanks again for
> the ideas.
>
>
> Earle Horton wrote:
> > The sender unit consists of a float attached to a moveable arm, that
moves a
> > variable resistor. The electrical resistance at the sender unit
terminals
> > will change as the arm is moved. I can tell you right now, that the
Haynes
> > Automotive Repair Manual that I have, part number 50030 (1777), for the
1987
> > through 1995 Jeep Wrangler, does not contain the resistance values, that
you
> > need to test the sender unit. :o( A cursory scan of that section of the
> > manual indicates, that it may be useful for removing the tank. I
suggest
> > removing the tank, to inspect the sender unit. :o(
> >
> > The sender unit is tested electrically, by moving the arm with a DVOM
(Drive
> > Vehicle Off Mountain or Digital Volt Ohm Meter, I can't remember which)
> > attached to the sender unit terminals. The resistance should change
> > smoothly as the arm is moved. Lacking the specifications, I can't tell
you
> > more. If the float is saturated or full of fuel, it will feel heavy or
make
> > a sloshing sound.
> >
> > Other suspects are a faulty electrical connection at the fuel
pump/sender
> > unit connector, a fault in the wiring to the sender unit, and a bad
gauge.
> > If you can identify and access the wires to the sender unit (Haynes
wiring
> > diagrams are pretty bad too) then you can check for voltage to the
sender
> > unit with the key on. We used to short the terminal to ground, and
watch
> > the gauge go to full, on some older vehicles, but I do not know whether
this
> > is recommended for your vehicle. The Haynes manual is short on
> > troubleshooting tips in this area.
> >
> > It does sound as if the price quoted, is for a sender/fuel pump unit.
They
> > appear to be a single unit. On vehicles with a 20 gallon tank, the fuel
> > pump/sender unit is mounted with eight screws. The fifteen gallon tank
has
> > a lock ring. The Haynes manual says "if the ring is difficult to
remove,
> > tap it loose with a wood dowel or brass punch and a small mallet (DO NOT
use
> > a steel punch, or you could cause an explosion!)" They show a steel
> > screwdriver being used.
> >
> > The behavior of your gauge is consistent with a flooded float, but not a
> > 100% indication. On my old Plymouth Valiant, this was a fifteen minute
job,
> > if the tank was below one quarter full. Things sure have changed. My
> > advice is to get some penetrating oil on the tank mounting bolts, a
couple
> > of days before you try dropping the tank.
> >
> > Earle
> >
> > "Joe and Joann" <mauijoeb@removehawaii.rr.com> wrote in message
> > news:EKV5g.11377$MP2.1636@tornado.socal.rr.com...
> >> I have a 90 YJ Sahara 4.2 L with about 70K miles. The fuel guage just
> >> stopped working. It always reads zero or almost zero.The rest of the
> >> guages working OK. My guess is the sending unit. Any other likely
> >> possibilities. The dealer wanted nearly $250 for A new sender (not
> >> including installation) This seems a bit high to me, more like the
price
> >> for the FI unit that includes the pump. Is there anyway to isolate the
> >> problem to the guage itself rather than the sender. If it is important,
> >> the guage does move slightly to the right when the power is turned on,
> >> but only gets to empty.
> >>
> >> So assuming it is the sender and I can find one, any tips on dropping
> >> the tank. Also is there any way to tell the difference between the 14.5
> >> gallon tank and the 20. Pretty sure I have the smaller tank, but I
never
> >> let it get very low, so I am not sure.
> >>
> >> Aloha from Maui
> >> Joe
> >
> >
number of significant changes, and the manual doesn't even discuss the
possibility of a fuel tank without an electric fuel pump in it.
If you have a saturated float, sometimes they can be repaired. If you have
another vehicle, it would be good to identify for sure which part is busted,
before spending $250 on a sender.
Earle
"Joe and Joann" <mauijoeb@removehawaii.rr.com> wrote in message
news:NfX5g.11379$MP2.1027@tornado.socal.rr.com...
> Thanks Earl
> Since I have the carb 4.2 L with the mechanical pump, I sure don't need
> the in the tank pump used on the FI model. Hard to believe that price
> isn't for the combined pump/sender unit as you said. Thanks again for
> the ideas.
>
>
> Earle Horton wrote:
> > The sender unit consists of a float attached to a moveable arm, that
moves a
> > variable resistor. The electrical resistance at the sender unit
terminals
> > will change as the arm is moved. I can tell you right now, that the
Haynes
> > Automotive Repair Manual that I have, part number 50030 (1777), for the
1987
> > through 1995 Jeep Wrangler, does not contain the resistance values, that
you
> > need to test the sender unit. :o( A cursory scan of that section of the
> > manual indicates, that it may be useful for removing the tank. I
suggest
> > removing the tank, to inspect the sender unit. :o(
> >
> > The sender unit is tested electrically, by moving the arm with a DVOM
(Drive
> > Vehicle Off Mountain or Digital Volt Ohm Meter, I can't remember which)
> > attached to the sender unit terminals. The resistance should change
> > smoothly as the arm is moved. Lacking the specifications, I can't tell
you
> > more. If the float is saturated or full of fuel, it will feel heavy or
make
> > a sloshing sound.
> >
> > Other suspects are a faulty electrical connection at the fuel
pump/sender
> > unit connector, a fault in the wiring to the sender unit, and a bad
gauge.
> > If you can identify and access the wires to the sender unit (Haynes
wiring
> > diagrams are pretty bad too) then you can check for voltage to the
sender
> > unit with the key on. We used to short the terminal to ground, and
watch
> > the gauge go to full, on some older vehicles, but I do not know whether
this
> > is recommended for your vehicle. The Haynes manual is short on
> > troubleshooting tips in this area.
> >
> > It does sound as if the price quoted, is for a sender/fuel pump unit.
They
> > appear to be a single unit. On vehicles with a 20 gallon tank, the fuel
> > pump/sender unit is mounted with eight screws. The fifteen gallon tank
has
> > a lock ring. The Haynes manual says "if the ring is difficult to
remove,
> > tap it loose with a wood dowel or brass punch and a small mallet (DO NOT
use
> > a steel punch, or you could cause an explosion!)" They show a steel
> > screwdriver being used.
> >
> > The behavior of your gauge is consistent with a flooded float, but not a
> > 100% indication. On my old Plymouth Valiant, this was a fifteen minute
job,
> > if the tank was below one quarter full. Things sure have changed. My
> > advice is to get some penetrating oil on the tank mounting bolts, a
couple
> > of days before you try dropping the tank.
> >
> > Earle
> >
> > "Joe and Joann" <mauijoeb@removehawaii.rr.com> wrote in message
> > news:EKV5g.11377$MP2.1636@tornado.socal.rr.com...
> >> I have a 90 YJ Sahara 4.2 L with about 70K miles. The fuel guage just
> >> stopped working. It always reads zero or almost zero.The rest of the
> >> guages working OK. My guess is the sending unit. Any other likely
> >> possibilities. The dealer wanted nearly $250 for A new sender (not
> >> including installation) This seems a bit high to me, more like the
price
> >> for the FI unit that includes the pump. Is there anyway to isolate the
> >> problem to the guage itself rather than the sender. If it is important,
> >> the guage does move slightly to the right when the power is turned on,
> >> but only gets to empty.
> >>
> >> So assuming it is the sender and I can find one, any tips on dropping
> >> the tank. Also is there any way to tell the difference between the 14.5
> >> gallon tank and the 20. Pretty sure I have the smaller tank, but I
never
> >> let it get very low, so I am not sure.
> >>
> >> Aloha from Maui
> >> Joe
> >
> >
05-03-2006, 11:06 AM
#16
Guest
Posts: n/a
Re: Fuel Guage not working
Sorry, but this Haynes manual is terrible. That range of model years had a
number of significant changes, and the manual doesn't even discuss the
possibility of a fuel tank without an electric fuel pump in it.
If you have a saturated float, sometimes they can be repaired. If you have
another vehicle, it would be good to identify for sure which part is busted,
before spending $250 on a sender.
Earle
"Joe and Joann" <mauijoeb@removehawaii.rr.com> wrote in message
news:NfX5g.11379$MP2.1027@tornado.socal.rr.com...
> Thanks Earl
> Since I have the carb 4.2 L with the mechanical pump, I sure don't need
> the in the tank pump used on the FI model. Hard to believe that price
> isn't for the combined pump/sender unit as you said. Thanks again for
> the ideas.
>
>
> Earle Horton wrote:
> > The sender unit consists of a float attached to a moveable arm, that
moves a
> > variable resistor. The electrical resistance at the sender unit
terminals
> > will change as the arm is moved. I can tell you right now, that the
Haynes
> > Automotive Repair Manual that I have, part number 50030 (1777), for the
1987
> > through 1995 Jeep Wrangler, does not contain the resistance values, that
you
> > need to test the sender unit. :o( A cursory scan of that section of the
> > manual indicates, that it may be useful for removing the tank. I
suggest
> > removing the tank, to inspect the sender unit. :o(
> >
> > The sender unit is tested electrically, by moving the arm with a DVOM
(Drive
> > Vehicle Off Mountain or Digital Volt Ohm Meter, I can't remember which)
> > attached to the sender unit terminals. The resistance should change
> > smoothly as the arm is moved. Lacking the specifications, I can't tell
you
> > more. If the float is saturated or full of fuel, it will feel heavy or
make
> > a sloshing sound.
> >
> > Other suspects are a faulty electrical connection at the fuel
pump/sender
> > unit connector, a fault in the wiring to the sender unit, and a bad
gauge.
> > If you can identify and access the wires to the sender unit (Haynes
wiring
> > diagrams are pretty bad too) then you can check for voltage to the
sender
> > unit with the key on. We used to short the terminal to ground, and
watch
> > the gauge go to full, on some older vehicles, but I do not know whether
this
> > is recommended for your vehicle. The Haynes manual is short on
> > troubleshooting tips in this area.
> >
> > It does sound as if the price quoted, is for a sender/fuel pump unit.
They
> > appear to be a single unit. On vehicles with a 20 gallon tank, the fuel
> > pump/sender unit is mounted with eight screws. The fifteen gallon tank
has
> > a lock ring. The Haynes manual says "if the ring is difficult to
remove,
> > tap it loose with a wood dowel or brass punch and a small mallet (DO NOT
use
> > a steel punch, or you could cause an explosion!)" They show a steel
> > screwdriver being used.
> >
> > The behavior of your gauge is consistent with a flooded float, but not a
> > 100% indication. On my old Plymouth Valiant, this was a fifteen minute
job,
> > if the tank was below one quarter full. Things sure have changed. My
> > advice is to get some penetrating oil on the tank mounting bolts, a
couple
> > of days before you try dropping the tank.
> >
> > Earle
> >
> > "Joe and Joann" <mauijoeb@removehawaii.rr.com> wrote in message
> > news:EKV5g.11377$MP2.1636@tornado.socal.rr.com...
> >> I have a 90 YJ Sahara 4.2 L with about 70K miles. The fuel guage just
> >> stopped working. It always reads zero or almost zero.The rest of the
> >> guages working OK. My guess is the sending unit. Any other likely
> >> possibilities. The dealer wanted nearly $250 for A new sender (not
> >> including installation) This seems a bit high to me, more like the
price
> >> for the FI unit that includes the pump. Is there anyway to isolate the
> >> problem to the guage itself rather than the sender. If it is important,
> >> the guage does move slightly to the right when the power is turned on,
> >> but only gets to empty.
> >>
> >> So assuming it is the sender and I can find one, any tips on dropping
> >> the tank. Also is there any way to tell the difference between the 14.5
> >> gallon tank and the 20. Pretty sure I have the smaller tank, but I
never
> >> let it get very low, so I am not sure.
> >>
> >> Aloha from Maui
> >> Joe
> >
> >
number of significant changes, and the manual doesn't even discuss the
possibility of a fuel tank without an electric fuel pump in it.
If you have a saturated float, sometimes they can be repaired. If you have
another vehicle, it would be good to identify for sure which part is busted,
before spending $250 on a sender.
Earle
"Joe and Joann" <mauijoeb@removehawaii.rr.com> wrote in message
news:NfX5g.11379$MP2.1027@tornado.socal.rr.com...
> Thanks Earl
> Since I have the carb 4.2 L with the mechanical pump, I sure don't need
> the in the tank pump used on the FI model. Hard to believe that price
> isn't for the combined pump/sender unit as you said. Thanks again for
> the ideas.
>
>
> Earle Horton wrote:
> > The sender unit consists of a float attached to a moveable arm, that
moves a
> > variable resistor. The electrical resistance at the sender unit
terminals
> > will change as the arm is moved. I can tell you right now, that the
Haynes
> > Automotive Repair Manual that I have, part number 50030 (1777), for the
1987
> > through 1995 Jeep Wrangler, does not contain the resistance values, that
you
> > need to test the sender unit. :o( A cursory scan of that section of the
> > manual indicates, that it may be useful for removing the tank. I
suggest
> > removing the tank, to inspect the sender unit. :o(
> >
> > The sender unit is tested electrically, by moving the arm with a DVOM
(Drive
> > Vehicle Off Mountain or Digital Volt Ohm Meter, I can't remember which)
> > attached to the sender unit terminals. The resistance should change
> > smoothly as the arm is moved. Lacking the specifications, I can't tell
you
> > more. If the float is saturated or full of fuel, it will feel heavy or
make
> > a sloshing sound.
> >
> > Other suspects are a faulty electrical connection at the fuel
pump/sender
> > unit connector, a fault in the wiring to the sender unit, and a bad
gauge.
> > If you can identify and access the wires to the sender unit (Haynes
wiring
> > diagrams are pretty bad too) then you can check for voltage to the
sender
> > unit with the key on. We used to short the terminal to ground, and
watch
> > the gauge go to full, on some older vehicles, but I do not know whether
this
> > is recommended for your vehicle. The Haynes manual is short on
> > troubleshooting tips in this area.
> >
> > It does sound as if the price quoted, is for a sender/fuel pump unit.
They
> > appear to be a single unit. On vehicles with a 20 gallon tank, the fuel
> > pump/sender unit is mounted with eight screws. The fifteen gallon tank
has
> > a lock ring. The Haynes manual says "if the ring is difficult to
remove,
> > tap it loose with a wood dowel or brass punch and a small mallet (DO NOT
use
> > a steel punch, or you could cause an explosion!)" They show a steel
> > screwdriver being used.
> >
> > The behavior of your gauge is consistent with a flooded float, but not a
> > 100% indication. On my old Plymouth Valiant, this was a fifteen minute
job,
> > if the tank was below one quarter full. Things sure have changed. My
> > advice is to get some penetrating oil on the tank mounting bolts, a
couple
> > of days before you try dropping the tank.
> >
> > Earle
> >
> > "Joe and Joann" <mauijoeb@removehawaii.rr.com> wrote in message
> > news:EKV5g.11377$MP2.1636@tornado.socal.rr.com...
> >> I have a 90 YJ Sahara 4.2 L with about 70K miles. The fuel guage just
> >> stopped working. It always reads zero or almost zero.The rest of the
> >> guages working OK. My guess is the sending unit. Any other likely
> >> possibilities. The dealer wanted nearly $250 for A new sender (not
> >> including installation) This seems a bit high to me, more like the
price
> >> for the FI unit that includes the pump. Is there anyway to isolate the
> >> problem to the guage itself rather than the sender. If it is important,
> >> the guage does move slightly to the right when the power is turned on,
> >> but only gets to empty.
> >>
> >> So assuming it is the sender and I can find one, any tips on dropping
> >> the tank. Also is there any way to tell the difference between the 14.5
> >> gallon tank and the 20. Pretty sure I have the smaller tank, but I
never
> >> let it get very low, so I am not sure.
> >>
> >> Aloha from Maui
> >> Joe
> >
> >
05-03-2006, 11:20 AM
#17
Guest
Posts: n/a
Re: Fuel Guage not working
For that year of a YJ, the Haynes CJ manual is excellent. That YJ uses
the CJ engine controls and the CJ underhood wiring harness.
Mike
Earle Horton wrote:
>
> Sorry, but this Haynes manual is terrible. That range of model years had a
> number of significant changes, and the manual doesn't even discuss the
> possibility of a fuel tank without an electric fuel pump in it.
>
> If you have a saturated float, sometimes they can be repaired. If you have
> another vehicle, it would be good to identify for sure which part is busted,
> before spending $250 on a sender.
>
> Earle
>
> "Joe and Joann" <mauijoeb@removehawaii.rr.com> wrote in message
> news:NfX5g.11379$MP2.1027@tornado.socal.rr.com...
> > Thanks Earl
> > Since I have the carb 4.2 L with the mechanical pump, I sure don't need
> > the in the tank pump used on the FI model. Hard to believe that price
> > isn't for the combined pump/sender unit as you said. Thanks again for
> > the ideas.
> >
> >
> > Earle Horton wrote:
> > > The sender unit consists of a float attached to a moveable arm, that
> moves a
> > > variable resistor. The electrical resistance at the sender unit
> terminals
> > > will change as the arm is moved. I can tell you right now, that the
> Haynes
> > > Automotive Repair Manual that I have, part number 50030 (1777), for the
> 1987
> > > through 1995 Jeep Wrangler, does not contain the resistance values, that
> you
> > > need to test the sender unit. :o( A cursory scan of that section of the
> > > manual indicates, that it may be useful for removing the tank. I
> suggest
> > > removing the tank, to inspect the sender unit. :o(
> > >
> > > The sender unit is tested electrically, by moving the arm with a DVOM
> (Drive
> > > Vehicle Off Mountain or Digital Volt Ohm Meter, I can't remember which)
> > > attached to the sender unit terminals. The resistance should change
> > > smoothly as the arm is moved. Lacking the specifications, I can't tell
> you
> > > more. If the float is saturated or full of fuel, it will feel heavy or
> make
> > > a sloshing sound.
> > >
> > > Other suspects are a faulty electrical connection at the fuel
> pump/sender
> > > unit connector, a fault in the wiring to the sender unit, and a bad
> gauge.
> > > If you can identify and access the wires to the sender unit (Haynes
> wiring
> > > diagrams are pretty bad too) then you can check for voltage to the
> sender
> > > unit with the key on. We used to short the terminal to ground, and
> watch
> > > the gauge go to full, on some older vehicles, but I do not know whether
> this
> > > is recommended for your vehicle. The Haynes manual is short on
> > > troubleshooting tips in this area.
> > >
> > > It does sound as if the price quoted, is for a sender/fuel pump unit.
> They
> > > appear to be a single unit. On vehicles with a 20 gallon tank, the fuel
> > > pump/sender unit is mounted with eight screws. The fifteen gallon tank
> has
> > > a lock ring. The Haynes manual says "if the ring is difficult to
> remove,
> > > tap it loose with a wood dowel or brass punch and a small mallet (DO NOT
> use
> > > a steel punch, or you could cause an explosion!)" They show a steel
> > > screwdriver being used.
> > >
> > > The behavior of your gauge is consistent with a flooded float, but not a
> > > 100% indication. On my old Plymouth Valiant, this was a fifteen minute
> job,
> > > if the tank was below one quarter full. Things sure have changed. My
> > > advice is to get some penetrating oil on the tank mounting bolts, a
> couple
> > > of days before you try dropping the tank.
> > >
> > > Earle
> > >
> > > "Joe and Joann" <mauijoeb@removehawaii.rr.com> wrote in message
> > > news:EKV5g.11377$MP2.1636@tornado.socal.rr.com...
> > >> I have a 90 YJ Sahara 4.2 L with about 70K miles. The fuel guage just
> > >> stopped working. It always reads zero or almost zero.The rest of the
> > >> guages working OK. My guess is the sending unit. Any other likely
> > >> possibilities. The dealer wanted nearly $250 for A new sender (not
> > >> including installation) This seems a bit high to me, more like the
> price
> > >> for the FI unit that includes the pump. Is there anyway to isolate the
> > >> problem to the guage itself rather than the sender. If it is important,
> > >> the guage does move slightly to the right when the power is turned on,
> > >> but only gets to empty.
> > >>
> > >> So assuming it is the sender and I can find one, any tips on dropping
> > >> the tank. Also is there any way to tell the difference between the 14.5
> > >> gallon tank and the 20. Pretty sure I have the smaller tank, but I
> never
> > >> let it get very low, so I am not sure.
> > >>
> > >> Aloha from Maui
> > >> Joe
> > >
> > >
the CJ engine controls and the CJ underhood wiring harness.
Mike
Earle Horton wrote:
>
> Sorry, but this Haynes manual is terrible. That range of model years had a
> number of significant changes, and the manual doesn't even discuss the
> possibility of a fuel tank without an electric fuel pump in it.
>
> If you have a saturated float, sometimes they can be repaired. If you have
> another vehicle, it would be good to identify for sure which part is busted,
> before spending $250 on a sender.
>
> Earle
>
> "Joe and Joann" <mauijoeb@removehawaii.rr.com> wrote in message
> news:NfX5g.11379$MP2.1027@tornado.socal.rr.com...
> > Thanks Earl
> > Since I have the carb 4.2 L with the mechanical pump, I sure don't need
> > the in the tank pump used on the FI model. Hard to believe that price
> > isn't for the combined pump/sender unit as you said. Thanks again for
> > the ideas.
> >
> >
> > Earle Horton wrote:
> > > The sender unit consists of a float attached to a moveable arm, that
> moves a
> > > variable resistor. The electrical resistance at the sender unit
> terminals
> > > will change as the arm is moved. I can tell you right now, that the
> Haynes
> > > Automotive Repair Manual that I have, part number 50030 (1777), for the
> 1987
> > > through 1995 Jeep Wrangler, does not contain the resistance values, that
> you
> > > need to test the sender unit. :o( A cursory scan of that section of the
> > > manual indicates, that it may be useful for removing the tank. I
> suggest
> > > removing the tank, to inspect the sender unit. :o(
> > >
> > > The sender unit is tested electrically, by moving the arm with a DVOM
> (Drive
> > > Vehicle Off Mountain or Digital Volt Ohm Meter, I can't remember which)
> > > attached to the sender unit terminals. The resistance should change
> > > smoothly as the arm is moved. Lacking the specifications, I can't tell
> you
> > > more. If the float is saturated or full of fuel, it will feel heavy or
> make
> > > a sloshing sound.
> > >
> > > Other suspects are a faulty electrical connection at the fuel
> pump/sender
> > > unit connector, a fault in the wiring to the sender unit, and a bad
> gauge.
> > > If you can identify and access the wires to the sender unit (Haynes
> wiring
> > > diagrams are pretty bad too) then you can check for voltage to the
> sender
> > > unit with the key on. We used to short the terminal to ground, and
> watch
> > > the gauge go to full, on some older vehicles, but I do not know whether
> this
> > > is recommended for your vehicle. The Haynes manual is short on
> > > troubleshooting tips in this area.
> > >
> > > It does sound as if the price quoted, is for a sender/fuel pump unit.
> They
> > > appear to be a single unit. On vehicles with a 20 gallon tank, the fuel
> > > pump/sender unit is mounted with eight screws. The fifteen gallon tank
> has
> > > a lock ring. The Haynes manual says "if the ring is difficult to
> remove,
> > > tap it loose with a wood dowel or brass punch and a small mallet (DO NOT
> use
> > > a steel punch, or you could cause an explosion!)" They show a steel
> > > screwdriver being used.
> > >
> > > The behavior of your gauge is consistent with a flooded float, but not a
> > > 100% indication. On my old Plymouth Valiant, this was a fifteen minute
> job,
> > > if the tank was below one quarter full. Things sure have changed. My
> > > advice is to get some penetrating oil on the tank mounting bolts, a
> couple
> > > of days before you try dropping the tank.
> > >
> > > Earle
> > >
> > > "Joe and Joann" <mauijoeb@removehawaii.rr.com> wrote in message
> > > news:EKV5g.11377$MP2.1636@tornado.socal.rr.com...
> > >> I have a 90 YJ Sahara 4.2 L with about 70K miles. The fuel guage just
> > >> stopped working. It always reads zero or almost zero.The rest of the
> > >> guages working OK. My guess is the sending unit. Any other likely
> > >> possibilities. The dealer wanted nearly $250 for A new sender (not
> > >> including installation) This seems a bit high to me, more like the
> price
> > >> for the FI unit that includes the pump. Is there anyway to isolate the
> > >> problem to the guage itself rather than the sender. If it is important,
> > >> the guage does move slightly to the right when the power is turned on,
> > >> but only gets to empty.
> > >>
> > >> So assuming it is the sender and I can find one, any tips on dropping
> > >> the tank. Also is there any way to tell the difference between the 14.5
> > >> gallon tank and the 20. Pretty sure I have the smaller tank, but I
> never
> > >> let it get very low, so I am not sure.
> > >>
> > >> Aloha from Maui
> > >> Joe
> > >
> > >
05-03-2006, 11:20 AM
#18
Guest
Posts: n/a
Re: Fuel Guage not working
For that year of a YJ, the Haynes CJ manual is excellent. That YJ uses
the CJ engine controls and the CJ underhood wiring harness.
Mike
Earle Horton wrote:
>
> Sorry, but this Haynes manual is terrible. That range of model years had a
> number of significant changes, and the manual doesn't even discuss the
> possibility of a fuel tank without an electric fuel pump in it.
>
> If you have a saturated float, sometimes they can be repaired. If you have
> another vehicle, it would be good to identify for sure which part is busted,
> before spending $250 on a sender.
>
> Earle
>
> "Joe and Joann" <mauijoeb@removehawaii.rr.com> wrote in message
> news:NfX5g.11379$MP2.1027@tornado.socal.rr.com...
> > Thanks Earl
> > Since I have the carb 4.2 L with the mechanical pump, I sure don't need
> > the in the tank pump used on the FI model. Hard to believe that price
> > isn't for the combined pump/sender unit as you said. Thanks again for
> > the ideas.
> >
> >
> > Earle Horton wrote:
> > > The sender unit consists of a float attached to a moveable arm, that
> moves a
> > > variable resistor. The electrical resistance at the sender unit
> terminals
> > > will change as the arm is moved. I can tell you right now, that the
> Haynes
> > > Automotive Repair Manual that I have, part number 50030 (1777), for the
> 1987
> > > through 1995 Jeep Wrangler, does not contain the resistance values, that
> you
> > > need to test the sender unit. :o( A cursory scan of that section of the
> > > manual indicates, that it may be useful for removing the tank. I
> suggest
> > > removing the tank, to inspect the sender unit. :o(
> > >
> > > The sender unit is tested electrically, by moving the arm with a DVOM
> (Drive
> > > Vehicle Off Mountain or Digital Volt Ohm Meter, I can't remember which)
> > > attached to the sender unit terminals. The resistance should change
> > > smoothly as the arm is moved. Lacking the specifications, I can't tell
> you
> > > more. If the float is saturated or full of fuel, it will feel heavy or
> make
> > > a sloshing sound.
> > >
> > > Other suspects are a faulty electrical connection at the fuel
> pump/sender
> > > unit connector, a fault in the wiring to the sender unit, and a bad
> gauge.
> > > If you can identify and access the wires to the sender unit (Haynes
> wiring
> > > diagrams are pretty bad too) then you can check for voltage to the
> sender
> > > unit with the key on. We used to short the terminal to ground, and
> watch
> > > the gauge go to full, on some older vehicles, but I do not know whether
> this
> > > is recommended for your vehicle. The Haynes manual is short on
> > > troubleshooting tips in this area.
> > >
> > > It does sound as if the price quoted, is for a sender/fuel pump unit.
> They
> > > appear to be a single unit. On vehicles with a 20 gallon tank, the fuel
> > > pump/sender unit is mounted with eight screws. The fifteen gallon tank
> has
> > > a lock ring. The Haynes manual says "if the ring is difficult to
> remove,
> > > tap it loose with a wood dowel or brass punch and a small mallet (DO NOT
> use
> > > a steel punch, or you could cause an explosion!)" They show a steel
> > > screwdriver being used.
> > >
> > > The behavior of your gauge is consistent with a flooded float, but not a
> > > 100% indication. On my old Plymouth Valiant, this was a fifteen minute
> job,
> > > if the tank was below one quarter full. Things sure have changed. My
> > > advice is to get some penetrating oil on the tank mounting bolts, a
> couple
> > > of days before you try dropping the tank.
> > >
> > > Earle
> > >
> > > "Joe and Joann" <mauijoeb@removehawaii.rr.com> wrote in message
> > > news:EKV5g.11377$MP2.1636@tornado.socal.rr.com...
> > >> I have a 90 YJ Sahara 4.2 L with about 70K miles. The fuel guage just
> > >> stopped working. It always reads zero or almost zero.The rest of the
> > >> guages working OK. My guess is the sending unit. Any other likely
> > >> possibilities. The dealer wanted nearly $250 for A new sender (not
> > >> including installation) This seems a bit high to me, more like the
> price
> > >> for the FI unit that includes the pump. Is there anyway to isolate the
> > >> problem to the guage itself rather than the sender. If it is important,
> > >> the guage does move slightly to the right when the power is turned on,
> > >> but only gets to empty.
> > >>
> > >> So assuming it is the sender and I can find one, any tips on dropping
> > >> the tank. Also is there any way to tell the difference between the 14.5
> > >> gallon tank and the 20. Pretty sure I have the smaller tank, but I
> never
> > >> let it get very low, so I am not sure.
> > >>
> > >> Aloha from Maui
> > >> Joe
> > >
> > >
the CJ engine controls and the CJ underhood wiring harness.
Mike
Earle Horton wrote:
>
> Sorry, but this Haynes manual is terrible. That range of model years had a
> number of significant changes, and the manual doesn't even discuss the
> possibility of a fuel tank without an electric fuel pump in it.
>
> If you have a saturated float, sometimes they can be repaired. If you have
> another vehicle, it would be good to identify for sure which part is busted,
> before spending $250 on a sender.
>
> Earle
>
> "Joe and Joann" <mauijoeb@removehawaii.rr.com> wrote in message
> news:NfX5g.11379$MP2.1027@tornado.socal.rr.com...
> > Thanks Earl
> > Since I have the carb 4.2 L with the mechanical pump, I sure don't need
> > the in the tank pump used on the FI model. Hard to believe that price
> > isn't for the combined pump/sender unit as you said. Thanks again for
> > the ideas.
> >
> >
> > Earle Horton wrote:
> > > The sender unit consists of a float attached to a moveable arm, that
> moves a
> > > variable resistor. The electrical resistance at the sender unit
> terminals
> > > will change as the arm is moved. I can tell you right now, that the
> Haynes
> > > Automotive Repair Manual that I have, part number 50030 (1777), for the
> 1987
> > > through 1995 Jeep Wrangler, does not contain the resistance values, that
> you
> > > need to test the sender unit. :o( A cursory scan of that section of the
> > > manual indicates, that it may be useful for removing the tank. I
> suggest
> > > removing the tank, to inspect the sender unit. :o(
> > >
> > > The sender unit is tested electrically, by moving the arm with a DVOM
> (Drive
> > > Vehicle Off Mountain or Digital Volt Ohm Meter, I can't remember which)
> > > attached to the sender unit terminals. The resistance should change
> > > smoothly as the arm is moved. Lacking the specifications, I can't tell
> you
> > > more. If the float is saturated or full of fuel, it will feel heavy or
> make
> > > a sloshing sound.
> > >
> > > Other suspects are a faulty electrical connection at the fuel
> pump/sender
> > > unit connector, a fault in the wiring to the sender unit, and a bad
> gauge.
> > > If you can identify and access the wires to the sender unit (Haynes
> wiring
> > > diagrams are pretty bad too) then you can check for voltage to the
> sender
> > > unit with the key on. We used to short the terminal to ground, and
> watch
> > > the gauge go to full, on some older vehicles, but I do not know whether
> this
> > > is recommended for your vehicle. The Haynes manual is short on
> > > troubleshooting tips in this area.
> > >
> > > It does sound as if the price quoted, is for a sender/fuel pump unit.
> They
> > > appear to be a single unit. On vehicles with a 20 gallon tank, the fuel
> > > pump/sender unit is mounted with eight screws. The fifteen gallon tank
> has
> > > a lock ring. The Haynes manual says "if the ring is difficult to
> remove,
> > > tap it loose with a wood dowel or brass punch and a small mallet (DO NOT
> use
> > > a steel punch, or you could cause an explosion!)" They show a steel
> > > screwdriver being used.
> > >
> > > The behavior of your gauge is consistent with a flooded float, but not a
> > > 100% indication. On my old Plymouth Valiant, this was a fifteen minute
> job,
> > > if the tank was below one quarter full. Things sure have changed. My
> > > advice is to get some penetrating oil on the tank mounting bolts, a
> couple
> > > of days before you try dropping the tank.
> > >
> > > Earle
> > >
> > > "Joe and Joann" <mauijoeb@removehawaii.rr.com> wrote in message
> > > news:EKV5g.11377$MP2.1636@tornado.socal.rr.com...
> > >> I have a 90 YJ Sahara 4.2 L with about 70K miles. The fuel guage just
> > >> stopped working. It always reads zero or almost zero.The rest of the
> > >> guages working OK. My guess is the sending unit. Any other likely
> > >> possibilities. The dealer wanted nearly $250 for A new sender (not
> > >> including installation) This seems a bit high to me, more like the
> price
> > >> for the FI unit that includes the pump. Is there anyway to isolate the
> > >> problem to the guage itself rather than the sender. If it is important,
> > >> the guage does move slightly to the right when the power is turned on,
> > >> but only gets to empty.
> > >>
> > >> So assuming it is the sender and I can find one, any tips on dropping
> > >> the tank. Also is there any way to tell the difference between the 14.5
> > >> gallon tank and the 20. Pretty sure I have the smaller tank, but I
> never
> > >> let it get very low, so I am not sure.
> > >>
> > >> Aloha from Maui
> > >> Joe
> > >
> > >
05-03-2006, 11:20 AM
#19
Guest
Posts: n/a
Re: Fuel Guage not working
For that year of a YJ, the Haynes CJ manual is excellent. That YJ uses
the CJ engine controls and the CJ underhood wiring harness.
Mike
Earle Horton wrote:
>
> Sorry, but this Haynes manual is terrible. That range of model years had a
> number of significant changes, and the manual doesn't even discuss the
> possibility of a fuel tank without an electric fuel pump in it.
>
> If you have a saturated float, sometimes they can be repaired. If you have
> another vehicle, it would be good to identify for sure which part is busted,
> before spending $250 on a sender.
>
> Earle
>
> "Joe and Joann" <mauijoeb@removehawaii.rr.com> wrote in message
> news:NfX5g.11379$MP2.1027@tornado.socal.rr.com...
> > Thanks Earl
> > Since I have the carb 4.2 L with the mechanical pump, I sure don't need
> > the in the tank pump used on the FI model. Hard to believe that price
> > isn't for the combined pump/sender unit as you said. Thanks again for
> > the ideas.
> >
> >
> > Earle Horton wrote:
> > > The sender unit consists of a float attached to a moveable arm, that
> moves a
> > > variable resistor. The electrical resistance at the sender unit
> terminals
> > > will change as the arm is moved. I can tell you right now, that the
> Haynes
> > > Automotive Repair Manual that I have, part number 50030 (1777), for the
> 1987
> > > through 1995 Jeep Wrangler, does not contain the resistance values, that
> you
> > > need to test the sender unit. :o( A cursory scan of that section of the
> > > manual indicates, that it may be useful for removing the tank. I
> suggest
> > > removing the tank, to inspect the sender unit. :o(
> > >
> > > The sender unit is tested electrically, by moving the arm with a DVOM
> (Drive
> > > Vehicle Off Mountain or Digital Volt Ohm Meter, I can't remember which)
> > > attached to the sender unit terminals. The resistance should change
> > > smoothly as the arm is moved. Lacking the specifications, I can't tell
> you
> > > more. If the float is saturated or full of fuel, it will feel heavy or
> make
> > > a sloshing sound.
> > >
> > > Other suspects are a faulty electrical connection at the fuel
> pump/sender
> > > unit connector, a fault in the wiring to the sender unit, and a bad
> gauge.
> > > If you can identify and access the wires to the sender unit (Haynes
> wiring
> > > diagrams are pretty bad too) then you can check for voltage to the
> sender
> > > unit with the key on. We used to short the terminal to ground, and
> watch
> > > the gauge go to full, on some older vehicles, but I do not know whether
> this
> > > is recommended for your vehicle. The Haynes manual is short on
> > > troubleshooting tips in this area.
> > >
> > > It does sound as if the price quoted, is for a sender/fuel pump unit.
> They
> > > appear to be a single unit. On vehicles with a 20 gallon tank, the fuel
> > > pump/sender unit is mounted with eight screws. The fifteen gallon tank
> has
> > > a lock ring. The Haynes manual says "if the ring is difficult to
> remove,
> > > tap it loose with a wood dowel or brass punch and a small mallet (DO NOT
> use
> > > a steel punch, or you could cause an explosion!)" They show a steel
> > > screwdriver being used.
> > >
> > > The behavior of your gauge is consistent with a flooded float, but not a
> > > 100% indication. On my old Plymouth Valiant, this was a fifteen minute
> job,
> > > if the tank was below one quarter full. Things sure have changed. My
> > > advice is to get some penetrating oil on the tank mounting bolts, a
> couple
> > > of days before you try dropping the tank.
> > >
> > > Earle
> > >
> > > "Joe and Joann" <mauijoeb@removehawaii.rr.com> wrote in message
> > > news:EKV5g.11377$MP2.1636@tornado.socal.rr.com...
> > >> I have a 90 YJ Sahara 4.2 L with about 70K miles. The fuel guage just
> > >> stopped working. It always reads zero or almost zero.The rest of the
> > >> guages working OK. My guess is the sending unit. Any other likely
> > >> possibilities. The dealer wanted nearly $250 for A new sender (not
> > >> including installation) This seems a bit high to me, more like the
> price
> > >> for the FI unit that includes the pump. Is there anyway to isolate the
> > >> problem to the guage itself rather than the sender. If it is important,
> > >> the guage does move slightly to the right when the power is turned on,
> > >> but only gets to empty.
> > >>
> > >> So assuming it is the sender and I can find one, any tips on dropping
> > >> the tank. Also is there any way to tell the difference between the 14.5
> > >> gallon tank and the 20. Pretty sure I have the smaller tank, but I
> never
> > >> let it get very low, so I am not sure.
> > >>
> > >> Aloha from Maui
> > >> Joe
> > >
> > >
the CJ engine controls and the CJ underhood wiring harness.
Mike
Earle Horton wrote:
>
> Sorry, but this Haynes manual is terrible. That range of model years had a
> number of significant changes, and the manual doesn't even discuss the
> possibility of a fuel tank without an electric fuel pump in it.
>
> If you have a saturated float, sometimes they can be repaired. If you have
> another vehicle, it would be good to identify for sure which part is busted,
> before spending $250 on a sender.
>
> Earle
>
> "Joe and Joann" <mauijoeb@removehawaii.rr.com> wrote in message
> news:NfX5g.11379$MP2.1027@tornado.socal.rr.com...
> > Thanks Earl
> > Since I have the carb 4.2 L with the mechanical pump, I sure don't need
> > the in the tank pump used on the FI model. Hard to believe that price
> > isn't for the combined pump/sender unit as you said. Thanks again for
> > the ideas.
> >
> >
> > Earle Horton wrote:
> > > The sender unit consists of a float attached to a moveable arm, that
> moves a
> > > variable resistor. The electrical resistance at the sender unit
> terminals
> > > will change as the arm is moved. I can tell you right now, that the
> Haynes
> > > Automotive Repair Manual that I have, part number 50030 (1777), for the
> 1987
> > > through 1995 Jeep Wrangler, does not contain the resistance values, that
> you
> > > need to test the sender unit. :o( A cursory scan of that section of the
> > > manual indicates, that it may be useful for removing the tank. I
> suggest
> > > removing the tank, to inspect the sender unit. :o(
> > >
> > > The sender unit is tested electrically, by moving the arm with a DVOM
> (Drive
> > > Vehicle Off Mountain or Digital Volt Ohm Meter, I can't remember which)
> > > attached to the sender unit terminals. The resistance should change
> > > smoothly as the arm is moved. Lacking the specifications, I can't tell
> you
> > > more. If the float is saturated or full of fuel, it will feel heavy or
> make
> > > a sloshing sound.
> > >
> > > Other suspects are a faulty electrical connection at the fuel
> pump/sender
> > > unit connector, a fault in the wiring to the sender unit, and a bad
> gauge.
> > > If you can identify and access the wires to the sender unit (Haynes
> wiring
> > > diagrams are pretty bad too) then you can check for voltage to the
> sender
> > > unit with the key on. We used to short the terminal to ground, and
> watch
> > > the gauge go to full, on some older vehicles, but I do not know whether
> this
> > > is recommended for your vehicle. The Haynes manual is short on
> > > troubleshooting tips in this area.
> > >
> > > It does sound as if the price quoted, is for a sender/fuel pump unit.
> They
> > > appear to be a single unit. On vehicles with a 20 gallon tank, the fuel
> > > pump/sender unit is mounted with eight screws. The fifteen gallon tank
> has
> > > a lock ring. The Haynes manual says "if the ring is difficult to
> remove,
> > > tap it loose with a wood dowel or brass punch and a small mallet (DO NOT
> use
> > > a steel punch, or you could cause an explosion!)" They show a steel
> > > screwdriver being used.
> > >
> > > The behavior of your gauge is consistent with a flooded float, but not a
> > > 100% indication. On my old Plymouth Valiant, this was a fifteen minute
> job,
> > > if the tank was below one quarter full. Things sure have changed. My
> > > advice is to get some penetrating oil on the tank mounting bolts, a
> couple
> > > of days before you try dropping the tank.
> > >
> > > Earle
> > >
> > > "Joe and Joann" <mauijoeb@removehawaii.rr.com> wrote in message
> > > news:EKV5g.11377$MP2.1636@tornado.socal.rr.com...
> > >> I have a 90 YJ Sahara 4.2 L with about 70K miles. The fuel guage just
> > >> stopped working. It always reads zero or almost zero.The rest of the
> > >> guages working OK. My guess is the sending unit. Any other likely
> > >> possibilities. The dealer wanted nearly $250 for A new sender (not
> > >> including installation) This seems a bit high to me, more like the
> price
> > >> for the FI unit that includes the pump. Is there anyway to isolate the
> > >> problem to the guage itself rather than the sender. If it is important,
> > >> the guage does move slightly to the right when the power is turned on,
> > >> but only gets to empty.
> > >>
> > >> So assuming it is the sender and I can find one, any tips on dropping
> > >> the tank. Also is there any way to tell the difference between the 14.5
> > >> gallon tank and the 20. Pretty sure I have the smaller tank, but I
> never
> > >> let it get very low, so I am not sure.
> > >>
> > >> Aloha from Maui
> > >> Joe
> > >
> > >
05-03-2006, 08:20 PM
#20
Guest
Posts: n/a
Re: Fuel Guage not working
Aloha
Well, an interesting thing happened. I had refueled yesterday and the
guage still didn't move off empty. Today I was driving and the guage
went up to full and has been working steadily since then. Thanks to all
who replied. I am saving a copy of this thread so that when it comes
back I will be ready.
Meanwhile I will continue trying to track down a replacement at a
reasonable price. The Mopar parts on line shows one sender for 1990, but
it does't differentiate between the 20 and 15 gallon tank, nor FI or the
carbed I6. So I don't have a lot of confidence in that one. Its price is
$150 or so, at least better than the dealer.
The problem could be a bad ground, but it seems rock solid now. I would
think an intermittent ground would give more unsteady readings, but who
knows. Maybe the float was somehow stuck on empty.
By the way Mike, the tank is 51/2 inches below the rear cross member, so
itis the smaller tank.
Aloha from Maui and thanks Mike, Earle and Bill for the ideas
Well, an interesting thing happened. I had refueled yesterday and the
guage still didn't move off empty. Today I was driving and the guage
went up to full and has been working steadily since then. Thanks to all
who replied. I am saving a copy of this thread so that when it comes
back I will be ready.
Meanwhile I will continue trying to track down a replacement at a
reasonable price. The Mopar parts on line shows one sender for 1990, but
it does't differentiate between the 20 and 15 gallon tank, nor FI or the
carbed I6. So I don't have a lot of confidence in that one. Its price is
$150 or so, at least better than the dealer.
The problem could be a bad ground, but it seems rock solid now. I would
think an intermittent ground would give more unsteady readings, but who
knows. Maybe the float was somehow stuck on empty.
By the way Mike, the tank is 51/2 inches below the rear cross member, so
itis the smaller tank.
Aloha from Maui and thanks Mike, Earle and Bill for the ideas