Cherokee fuel press
#21
Guest
Posts: n/a
Re: Cherokee fuel press
Hmm, guys, I told you that my filter is brand new, pressure regulator is
new, filter on pump inlet was clean but pressure still behaves strange.
With or without vacuum line attached, pressure is always only 22 psi.
So, I drove around with gauge connected and mounted inside the cabin.
Happens that in the moment of "stalling" press drops to 18 psi (!?),
then it comes back to my 22 and rises a little bit , thing goes quite fine.
But nothing like in Haynes about 31 to even 39 psi!? Never.
Such a pressure never happens, even if I pinch return line (this is
even pain in the *** because only place where I can pinch return line is
down below the car just before tank. Everywhere else is plastic hose.)
Last thing remaining is stupid fuel pump. Has anyone had any problem
with fuel pump and how these problems look like on those cars?
Yes, one more thing, pressure remains same for a loong period after the
car has been stopped, so I assume that any kind of non-return valves
inside are still in a good mode. And I remember, when I changed filter
(few days ago), pressure rose to just about 24 psi and everything else
remain same.
L.W.(Bill) ------ III wrote:
> Hi Davey,
> I would guess it's at least the fuel regulator:
> http://members.***.net/wilsond/Fixes...tml#fuelsystem Pinch
> off the return line and you should have ninety pounds, if not replace
> the pump, too.
> God Bless America, Bill O|||||||O
> mailto:-------------------- http://www.----------.com/
>
> Davey wrote:
>
>> Few months ago, Jeep was at authorised workshop and guy hooked it up
>>on some kind a multitester for Chrysler/Jeep and complete test passed
>>through all of electronic items and found nothing wrong. Guy told me he
>>has no time to drive around with "tester thing" so we couldn't see what
>>happens when it comes to loaded 2250 rpm.
>>Mike, what about this fuel pressure, can it be just a damn pump?
>>Logically, when you pinch return hose, pressure should jump very fast,
>>right?
new, filter on pump inlet was clean but pressure still behaves strange.
With or without vacuum line attached, pressure is always only 22 psi.
So, I drove around with gauge connected and mounted inside the cabin.
Happens that in the moment of "stalling" press drops to 18 psi (!?),
then it comes back to my 22 and rises a little bit , thing goes quite fine.
But nothing like in Haynes about 31 to even 39 psi!? Never.
Such a pressure never happens, even if I pinch return line (this is
even pain in the *** because only place where I can pinch return line is
down below the car just before tank. Everywhere else is plastic hose.)
Last thing remaining is stupid fuel pump. Has anyone had any problem
with fuel pump and how these problems look like on those cars?
Yes, one more thing, pressure remains same for a loong period after the
car has been stopped, so I assume that any kind of non-return valves
inside are still in a good mode. And I remember, when I changed filter
(few days ago), pressure rose to just about 24 psi and everything else
remain same.
L.W.(Bill) ------ III wrote:
> Hi Davey,
> I would guess it's at least the fuel regulator:
> http://members.***.net/wilsond/Fixes...tml#fuelsystem Pinch
> off the return line and you should have ninety pounds, if not replace
> the pump, too.
> God Bless America, Bill O|||||||O
> mailto:-------------------- http://www.----------.com/
>
> Davey wrote:
>
>> Few months ago, Jeep was at authorised workshop and guy hooked it up
>>on some kind a multitester for Chrysler/Jeep and complete test passed
>>through all of electronic items and found nothing wrong. Guy told me he
>>has no time to drive around with "tester thing" so we couldn't see what
>>happens when it comes to loaded 2250 rpm.
>>Mike, what about this fuel pressure, can it be just a damn pump?
>>Logically, when you pinch return hose, pressure should jump very fast,
>>right?
#22
Guest
Posts: n/a
Re: Cherokee fuel press
Hmm, guys, I told you that my filter is brand new, pressure regulator is
new, filter on pump inlet was clean but pressure still behaves strange.
With or without vacuum line attached, pressure is always only 22 psi.
So, I drove around with gauge connected and mounted inside the cabin.
Happens that in the moment of "stalling" press drops to 18 psi (!?),
then it comes back to my 22 and rises a little bit , thing goes quite fine.
But nothing like in Haynes about 31 to even 39 psi!? Never.
Such a pressure never happens, even if I pinch return line (this is
even pain in the *** because only place where I can pinch return line is
down below the car just before tank. Everywhere else is plastic hose.)
Last thing remaining is stupid fuel pump. Has anyone had any problem
with fuel pump and how these problems look like on those cars?
Yes, one more thing, pressure remains same for a loong period after the
car has been stopped, so I assume that any kind of non-return valves
inside are still in a good mode. And I remember, when I changed filter
(few days ago), pressure rose to just about 24 psi and everything else
remain same.
L.W.(Bill) ------ III wrote:
> Hi Davey,
> I would guess it's at least the fuel regulator:
> http://members.***.net/wilsond/Fixes...tml#fuelsystem Pinch
> off the return line and you should have ninety pounds, if not replace
> the pump, too.
> God Bless America, Bill O|||||||O
> mailto:-------------------- http://www.----------.com/
>
> Davey wrote:
>
>> Few months ago, Jeep was at authorised workshop and guy hooked it up
>>on some kind a multitester for Chrysler/Jeep and complete test passed
>>through all of electronic items and found nothing wrong. Guy told me he
>>has no time to drive around with "tester thing" so we couldn't see what
>>happens when it comes to loaded 2250 rpm.
>>Mike, what about this fuel pressure, can it be just a damn pump?
>>Logically, when you pinch return hose, pressure should jump very fast,
>>right?
new, filter on pump inlet was clean but pressure still behaves strange.
With or without vacuum line attached, pressure is always only 22 psi.
So, I drove around with gauge connected and mounted inside the cabin.
Happens that in the moment of "stalling" press drops to 18 psi (!?),
then it comes back to my 22 and rises a little bit , thing goes quite fine.
But nothing like in Haynes about 31 to even 39 psi!? Never.
Such a pressure never happens, even if I pinch return line (this is
even pain in the *** because only place where I can pinch return line is
down below the car just before tank. Everywhere else is plastic hose.)
Last thing remaining is stupid fuel pump. Has anyone had any problem
with fuel pump and how these problems look like on those cars?
Yes, one more thing, pressure remains same for a loong period after the
car has been stopped, so I assume that any kind of non-return valves
inside are still in a good mode. And I remember, when I changed filter
(few days ago), pressure rose to just about 24 psi and everything else
remain same.
L.W.(Bill) ------ III wrote:
> Hi Davey,
> I would guess it's at least the fuel regulator:
> http://members.***.net/wilsond/Fixes...tml#fuelsystem Pinch
> off the return line and you should have ninety pounds, if not replace
> the pump, too.
> God Bless America, Bill O|||||||O
> mailto:-------------------- http://www.----------.com/
>
> Davey wrote:
>
>> Few months ago, Jeep was at authorised workshop and guy hooked it up
>>on some kind a multitester for Chrysler/Jeep and complete test passed
>>through all of electronic items and found nothing wrong. Guy told me he
>>has no time to drive around with "tester thing" so we couldn't see what
>>happens when it comes to loaded 2250 rpm.
>>Mike, what about this fuel pressure, can it be just a damn pump?
>>Logically, when you pinch return hose, pressure should jump very fast,
>>right?
#23
Guest
Posts: n/a
Re: Cherokee fuel press
Weak fuel pump.
Spdloader
"Davey" <davey@hi.t-com.hr> wrote in message
news:e2fngr$9k5$1@ss408.t-com.hr...
> Hmm, guys, I told you that my filter is brand new, pressure regulator is
> new, filter on pump inlet was clean but pressure still behaves strange.
> With or without vacuum line attached, pressure is always only 22 psi. So,
> I drove around with gauge connected and mounted inside the cabin. Happens
> that in the moment of "stalling" press drops to 18 psi (!?), then it comes
> back to my 22 and rises a little bit , thing goes quite fine.
> But nothing like in Haynes about 31 to even 39 psi!? Never.
> Such a pressure never happens, even if I pinch return line (this is even
> pain in the *** because only place where I can pinch return line is down
> below the car just before tank. Everywhere else is plastic hose.)
> Last thing remaining is stupid fuel pump. Has anyone had any problem with
> fuel pump and how these problems look like on those cars?
> Yes, one more thing, pressure remains same for a loong period after the
> car has been stopped, so I assume that any kind of non-return valves
> inside are still in a good mode. And I remember, when I changed filter
> (few days ago), pressure rose to just about 24 psi and everything else
> remain same.
>
> L.W.(Bill) ------ III wrote:
>> Hi Davey,
>> I would guess it's at least the fuel regulator:
>> http://members.***.net/wilsond/Fixes...tml#fuelsystem Pinch
>> off the return line and you should have ninety pounds, if not replace
>> the pump, too. God Bless America, Bill O|||||||O
>> mailto:-------------------- http://www.----------.com/
>>
>> Davey wrote:
>>
>>> Few months ago, Jeep was at authorised workshop and guy hooked it up
>>>on some kind a multitester for Chrysler/Jeep and complete test passed
>>>through all of electronic items and found nothing wrong. Guy told me he
>>>has no time to drive around with "tester thing" so we couldn't see what
>>>happens when it comes to loaded 2250 rpm.
>>>Mike, what about this fuel pressure, can it be just a damn pump?
>>>Logically, when you pinch return hose, pressure should jump very fast,
>>>right?
Spdloader
"Davey" <davey@hi.t-com.hr> wrote in message
news:e2fngr$9k5$1@ss408.t-com.hr...
> Hmm, guys, I told you that my filter is brand new, pressure regulator is
> new, filter on pump inlet was clean but pressure still behaves strange.
> With or without vacuum line attached, pressure is always only 22 psi. So,
> I drove around with gauge connected and mounted inside the cabin. Happens
> that in the moment of "stalling" press drops to 18 psi (!?), then it comes
> back to my 22 and rises a little bit , thing goes quite fine.
> But nothing like in Haynes about 31 to even 39 psi!? Never.
> Such a pressure never happens, even if I pinch return line (this is even
> pain in the *** because only place where I can pinch return line is down
> below the car just before tank. Everywhere else is plastic hose.)
> Last thing remaining is stupid fuel pump. Has anyone had any problem with
> fuel pump and how these problems look like on those cars?
> Yes, one more thing, pressure remains same for a loong period after the
> car has been stopped, so I assume that any kind of non-return valves
> inside are still in a good mode. And I remember, when I changed filter
> (few days ago), pressure rose to just about 24 psi and everything else
> remain same.
>
> L.W.(Bill) ------ III wrote:
>> Hi Davey,
>> I would guess it's at least the fuel regulator:
>> http://members.***.net/wilsond/Fixes...tml#fuelsystem Pinch
>> off the return line and you should have ninety pounds, if not replace
>> the pump, too. God Bless America, Bill O|||||||O
>> mailto:-------------------- http://www.----------.com/
>>
>> Davey wrote:
>>
>>> Few months ago, Jeep was at authorised workshop and guy hooked it up
>>>on some kind a multitester for Chrysler/Jeep and complete test passed
>>>through all of electronic items and found nothing wrong. Guy told me he
>>>has no time to drive around with "tester thing" so we couldn't see what
>>>happens when it comes to loaded 2250 rpm.
>>>Mike, what about this fuel pressure, can it be just a damn pump?
>>>Logically, when you pinch return hose, pressure should jump very fast,
>>>right?
#24
Guest
Posts: n/a
Re: Cherokee fuel press
Weak fuel pump.
Spdloader
"Davey" <davey@hi.t-com.hr> wrote in message
news:e2fngr$9k5$1@ss408.t-com.hr...
> Hmm, guys, I told you that my filter is brand new, pressure regulator is
> new, filter on pump inlet was clean but pressure still behaves strange.
> With or without vacuum line attached, pressure is always only 22 psi. So,
> I drove around with gauge connected and mounted inside the cabin. Happens
> that in the moment of "stalling" press drops to 18 psi (!?), then it comes
> back to my 22 and rises a little bit , thing goes quite fine.
> But nothing like in Haynes about 31 to even 39 psi!? Never.
> Such a pressure never happens, even if I pinch return line (this is even
> pain in the *** because only place where I can pinch return line is down
> below the car just before tank. Everywhere else is plastic hose.)
> Last thing remaining is stupid fuel pump. Has anyone had any problem with
> fuel pump and how these problems look like on those cars?
> Yes, one more thing, pressure remains same for a loong period after the
> car has been stopped, so I assume that any kind of non-return valves
> inside are still in a good mode. And I remember, when I changed filter
> (few days ago), pressure rose to just about 24 psi and everything else
> remain same.
>
> L.W.(Bill) ------ III wrote:
>> Hi Davey,
>> I would guess it's at least the fuel regulator:
>> http://members.***.net/wilsond/Fixes...tml#fuelsystem Pinch
>> off the return line and you should have ninety pounds, if not replace
>> the pump, too. God Bless America, Bill O|||||||O
>> mailto:-------------------- http://www.----------.com/
>>
>> Davey wrote:
>>
>>> Few months ago, Jeep was at authorised workshop and guy hooked it up
>>>on some kind a multitester for Chrysler/Jeep and complete test passed
>>>through all of electronic items and found nothing wrong. Guy told me he
>>>has no time to drive around with "tester thing" so we couldn't see what
>>>happens when it comes to loaded 2250 rpm.
>>>Mike, what about this fuel pressure, can it be just a damn pump?
>>>Logically, when you pinch return hose, pressure should jump very fast,
>>>right?
Spdloader
"Davey" <davey@hi.t-com.hr> wrote in message
news:e2fngr$9k5$1@ss408.t-com.hr...
> Hmm, guys, I told you that my filter is brand new, pressure regulator is
> new, filter on pump inlet was clean but pressure still behaves strange.
> With or without vacuum line attached, pressure is always only 22 psi. So,
> I drove around with gauge connected and mounted inside the cabin. Happens
> that in the moment of "stalling" press drops to 18 psi (!?), then it comes
> back to my 22 and rises a little bit , thing goes quite fine.
> But nothing like in Haynes about 31 to even 39 psi!? Never.
> Such a pressure never happens, even if I pinch return line (this is even
> pain in the *** because only place where I can pinch return line is down
> below the car just before tank. Everywhere else is plastic hose.)
> Last thing remaining is stupid fuel pump. Has anyone had any problem with
> fuel pump and how these problems look like on those cars?
> Yes, one more thing, pressure remains same for a loong period after the
> car has been stopped, so I assume that any kind of non-return valves
> inside are still in a good mode. And I remember, when I changed filter
> (few days ago), pressure rose to just about 24 psi and everything else
> remain same.
>
> L.W.(Bill) ------ III wrote:
>> Hi Davey,
>> I would guess it's at least the fuel regulator:
>> http://members.***.net/wilsond/Fixes...tml#fuelsystem Pinch
>> off the return line and you should have ninety pounds, if not replace
>> the pump, too. God Bless America, Bill O|||||||O
>> mailto:-------------------- http://www.----------.com/
>>
>> Davey wrote:
>>
>>> Few months ago, Jeep was at authorised workshop and guy hooked it up
>>>on some kind a multitester for Chrysler/Jeep and complete test passed
>>>through all of electronic items and found nothing wrong. Guy told me he
>>>has no time to drive around with "tester thing" so we couldn't see what
>>>happens when it comes to loaded 2250 rpm.
>>>Mike, what about this fuel pressure, can it be just a damn pump?
>>>Logically, when you pinch return hose, pressure should jump very fast,
>>>right?
#25
Guest
Posts: n/a
Re: Cherokee fuel press
Weak fuel pump.
Spdloader
"Davey" <davey@hi.t-com.hr> wrote in message
news:e2fngr$9k5$1@ss408.t-com.hr...
> Hmm, guys, I told you that my filter is brand new, pressure regulator is
> new, filter on pump inlet was clean but pressure still behaves strange.
> With or without vacuum line attached, pressure is always only 22 psi. So,
> I drove around with gauge connected and mounted inside the cabin. Happens
> that in the moment of "stalling" press drops to 18 psi (!?), then it comes
> back to my 22 and rises a little bit , thing goes quite fine.
> But nothing like in Haynes about 31 to even 39 psi!? Never.
> Such a pressure never happens, even if I pinch return line (this is even
> pain in the *** because only place where I can pinch return line is down
> below the car just before tank. Everywhere else is plastic hose.)
> Last thing remaining is stupid fuel pump. Has anyone had any problem with
> fuel pump and how these problems look like on those cars?
> Yes, one more thing, pressure remains same for a loong period after the
> car has been stopped, so I assume that any kind of non-return valves
> inside are still in a good mode. And I remember, when I changed filter
> (few days ago), pressure rose to just about 24 psi and everything else
> remain same.
>
> L.W.(Bill) ------ III wrote:
>> Hi Davey,
>> I would guess it's at least the fuel regulator:
>> http://members.***.net/wilsond/Fixes...tml#fuelsystem Pinch
>> off the return line and you should have ninety pounds, if not replace
>> the pump, too. God Bless America, Bill O|||||||O
>> mailto:-------------------- http://www.----------.com/
>>
>> Davey wrote:
>>
>>> Few months ago, Jeep was at authorised workshop and guy hooked it up
>>>on some kind a multitester for Chrysler/Jeep and complete test passed
>>>through all of electronic items and found nothing wrong. Guy told me he
>>>has no time to drive around with "tester thing" so we couldn't see what
>>>happens when it comes to loaded 2250 rpm.
>>>Mike, what about this fuel pressure, can it be just a damn pump?
>>>Logically, when you pinch return hose, pressure should jump very fast,
>>>right?
Spdloader
"Davey" <davey@hi.t-com.hr> wrote in message
news:e2fngr$9k5$1@ss408.t-com.hr...
> Hmm, guys, I told you that my filter is brand new, pressure regulator is
> new, filter on pump inlet was clean but pressure still behaves strange.
> With or without vacuum line attached, pressure is always only 22 psi. So,
> I drove around with gauge connected and mounted inside the cabin. Happens
> that in the moment of "stalling" press drops to 18 psi (!?), then it comes
> back to my 22 and rises a little bit , thing goes quite fine.
> But nothing like in Haynes about 31 to even 39 psi!? Never.
> Such a pressure never happens, even if I pinch return line (this is even
> pain in the *** because only place where I can pinch return line is down
> below the car just before tank. Everywhere else is plastic hose.)
> Last thing remaining is stupid fuel pump. Has anyone had any problem with
> fuel pump and how these problems look like on those cars?
> Yes, one more thing, pressure remains same for a loong period after the
> car has been stopped, so I assume that any kind of non-return valves
> inside are still in a good mode. And I remember, when I changed filter
> (few days ago), pressure rose to just about 24 psi and everything else
> remain same.
>
> L.W.(Bill) ------ III wrote:
>> Hi Davey,
>> I would guess it's at least the fuel regulator:
>> http://members.***.net/wilsond/Fixes...tml#fuelsystem Pinch
>> off the return line and you should have ninety pounds, if not replace
>> the pump, too. God Bless America, Bill O|||||||O
>> mailto:-------------------- http://www.----------.com/
>>
>> Davey wrote:
>>
>>> Few months ago, Jeep was at authorised workshop and guy hooked it up
>>>on some kind a multitester for Chrysler/Jeep and complete test passed
>>>through all of electronic items and found nothing wrong. Guy told me he
>>>has no time to drive around with "tester thing" so we couldn't see what
>>>happens when it comes to loaded 2250 rpm.
>>>Mike, what about this fuel pressure, can it be just a damn pump?
>>>Logically, when you pinch return hose, pressure should jump very fast,
>>>right?
#26
Guest
Posts: n/a
Re: Cherokee fuel press
Davey wrote:
>
> Mike Romain wrote:
> > I would be looking at the connection on the throttle position sensor
> > first. I use a spray contact cleaner on the connections on mine. WD40
> > will work as a connection cleaner too.
> >
> > They are a rheostat and can get a dead spot, but their electrical
> > connection can cause hiccups like you describe too. You can use a
> > multimeter on ohms and take the readings as you open the throttle with
> > it unplugged and the engine off. It should change evenly. If the
> > resistance bumps, you likely have found the trouble.
> >
> > I hear you can clean the guts of the TPS too, but have never needed to.
> >
> > 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)
> >
> Few months ago, Jeep was at authorised workshop and guy hooked it up
> on some kind a multitester for Chrysler/Jeep and complete test passed
> through all of electronic items and found nothing wrong. Guy told me he
> has no time to drive around with "tester thing" so we couldn't see what
> happens when it comes to loaded 2250 rpm.
> Mike, what about this fuel pressure, can it be just a damn pump?
> Logically, when you pinch return hose, pressure should jump very fast,
> right?
I live in the rust belt so usually look for bad connections first. They
are cheap and easy fixes. Our 88's fuel pump is run via a ceramic
ballast resistor that is out on the fender near the rad. That is open
to the elements and gets bad connections now and then.
The ground for the fuel pump is the body and the mesh strap from the
rear of the head to the firewall goes rotten easy not letting a
consistent circuit happen, but that usually causes stalls at speed like
a CPS going bad.
That TPS is known to give an acceleration hiccup though. It is cheap
and easy to clean it's connections just for the heck of it. Mine need a
clean it every two years or so.
I have seen fuel pump impellers come loose on Dodge and Chrysler
vehicles though. The suckers hum and draw power right, but just a
trickle comes out.
If you think you actually got the return line blocked, then that pump
could be suspect. Low power to the pump can cause it too though.
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)
>
> Mike Romain wrote:
> > I would be looking at the connection on the throttle position sensor
> > first. I use a spray contact cleaner on the connections on mine. WD40
> > will work as a connection cleaner too.
> >
> > They are a rheostat and can get a dead spot, but their electrical
> > connection can cause hiccups like you describe too. You can use a
> > multimeter on ohms and take the readings as you open the throttle with
> > it unplugged and the engine off. It should change evenly. If the
> > resistance bumps, you likely have found the trouble.
> >
> > I hear you can clean the guts of the TPS too, but have never needed to.
> >
> > 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)
> >
> Few months ago, Jeep was at authorised workshop and guy hooked it up
> on some kind a multitester for Chrysler/Jeep and complete test passed
> through all of electronic items and found nothing wrong. Guy told me he
> has no time to drive around with "tester thing" so we couldn't see what
> happens when it comes to loaded 2250 rpm.
> Mike, what about this fuel pressure, can it be just a damn pump?
> Logically, when you pinch return hose, pressure should jump very fast,
> right?
I live in the rust belt so usually look for bad connections first. They
are cheap and easy fixes. Our 88's fuel pump is run via a ceramic
ballast resistor that is out on the fender near the rad. That is open
to the elements and gets bad connections now and then.
The ground for the fuel pump is the body and the mesh strap from the
rear of the head to the firewall goes rotten easy not letting a
consistent circuit happen, but that usually causes stalls at speed like
a CPS going bad.
That TPS is known to give an acceleration hiccup though. It is cheap
and easy to clean it's connections just for the heck of it. Mine need a
clean it every two years or so.
I have seen fuel pump impellers come loose on Dodge and Chrysler
vehicles though. The suckers hum and draw power right, but just a
trickle comes out.
If you think you actually got the return line blocked, then that pump
could be suspect. Low power to the pump can cause it too though.
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)
#27
Guest
Posts: n/a
Re: Cherokee fuel press
Davey wrote:
>
> Mike Romain wrote:
> > I would be looking at the connection on the throttle position sensor
> > first. I use a spray contact cleaner on the connections on mine. WD40
> > will work as a connection cleaner too.
> >
> > They are a rheostat and can get a dead spot, but their electrical
> > connection can cause hiccups like you describe too. You can use a
> > multimeter on ohms and take the readings as you open the throttle with
> > it unplugged and the engine off. It should change evenly. If the
> > resistance bumps, you likely have found the trouble.
> >
> > I hear you can clean the guts of the TPS too, but have never needed to.
> >
> > 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)
> >
> Few months ago, Jeep was at authorised workshop and guy hooked it up
> on some kind a multitester for Chrysler/Jeep and complete test passed
> through all of electronic items and found nothing wrong. Guy told me he
> has no time to drive around with "tester thing" so we couldn't see what
> happens when it comes to loaded 2250 rpm.
> Mike, what about this fuel pressure, can it be just a damn pump?
> Logically, when you pinch return hose, pressure should jump very fast,
> right?
I live in the rust belt so usually look for bad connections first. They
are cheap and easy fixes. Our 88's fuel pump is run via a ceramic
ballast resistor that is out on the fender near the rad. That is open
to the elements and gets bad connections now and then.
The ground for the fuel pump is the body and the mesh strap from the
rear of the head to the firewall goes rotten easy not letting a
consistent circuit happen, but that usually causes stalls at speed like
a CPS going bad.
That TPS is known to give an acceleration hiccup though. It is cheap
and easy to clean it's connections just for the heck of it. Mine need a
clean it every two years or so.
I have seen fuel pump impellers come loose on Dodge and Chrysler
vehicles though. The suckers hum and draw power right, but just a
trickle comes out.
If you think you actually got the return line blocked, then that pump
could be suspect. Low power to the pump can cause it too though.
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)
>
> Mike Romain wrote:
> > I would be looking at the connection on the throttle position sensor
> > first. I use a spray contact cleaner on the connections on mine. WD40
> > will work as a connection cleaner too.
> >
> > They are a rheostat and can get a dead spot, but their electrical
> > connection can cause hiccups like you describe too. You can use a
> > multimeter on ohms and take the readings as you open the throttle with
> > it unplugged and the engine off. It should change evenly. If the
> > resistance bumps, you likely have found the trouble.
> >
> > I hear you can clean the guts of the TPS too, but have never needed to.
> >
> > 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)
> >
> Few months ago, Jeep was at authorised workshop and guy hooked it up
> on some kind a multitester for Chrysler/Jeep and complete test passed
> through all of electronic items and found nothing wrong. Guy told me he
> has no time to drive around with "tester thing" so we couldn't see what
> happens when it comes to loaded 2250 rpm.
> Mike, what about this fuel pressure, can it be just a damn pump?
> Logically, when you pinch return hose, pressure should jump very fast,
> right?
I live in the rust belt so usually look for bad connections first. They
are cheap and easy fixes. Our 88's fuel pump is run via a ceramic
ballast resistor that is out on the fender near the rad. That is open
to the elements and gets bad connections now and then.
The ground for the fuel pump is the body and the mesh strap from the
rear of the head to the firewall goes rotten easy not letting a
consistent circuit happen, but that usually causes stalls at speed like
a CPS going bad.
That TPS is known to give an acceleration hiccup though. It is cheap
and easy to clean it's connections just for the heck of it. Mine need a
clean it every two years or so.
I have seen fuel pump impellers come loose on Dodge and Chrysler
vehicles though. The suckers hum and draw power right, but just a
trickle comes out.
If you think you actually got the return line blocked, then that pump
could be suspect. Low power to the pump can cause it too though.
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)
#28
Guest
Posts: n/a
Re: Cherokee fuel press
Davey wrote:
>
> Mike Romain wrote:
> > I would be looking at the connection on the throttle position sensor
> > first. I use a spray contact cleaner on the connections on mine. WD40
> > will work as a connection cleaner too.
> >
> > They are a rheostat and can get a dead spot, but their electrical
> > connection can cause hiccups like you describe too. You can use a
> > multimeter on ohms and take the readings as you open the throttle with
> > it unplugged and the engine off. It should change evenly. If the
> > resistance bumps, you likely have found the trouble.
> >
> > I hear you can clean the guts of the TPS too, but have never needed to.
> >
> > 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)
> >
> Few months ago, Jeep was at authorised workshop and guy hooked it up
> on some kind a multitester for Chrysler/Jeep and complete test passed
> through all of electronic items and found nothing wrong. Guy told me he
> has no time to drive around with "tester thing" so we couldn't see what
> happens when it comes to loaded 2250 rpm.
> Mike, what about this fuel pressure, can it be just a damn pump?
> Logically, when you pinch return hose, pressure should jump very fast,
> right?
I live in the rust belt so usually look for bad connections first. They
are cheap and easy fixes. Our 88's fuel pump is run via a ceramic
ballast resistor that is out on the fender near the rad. That is open
to the elements and gets bad connections now and then.
The ground for the fuel pump is the body and the mesh strap from the
rear of the head to the firewall goes rotten easy not letting a
consistent circuit happen, but that usually causes stalls at speed like
a CPS going bad.
That TPS is known to give an acceleration hiccup though. It is cheap
and easy to clean it's connections just for the heck of it. Mine need a
clean it every two years or so.
I have seen fuel pump impellers come loose on Dodge and Chrysler
vehicles though. The suckers hum and draw power right, but just a
trickle comes out.
If you think you actually got the return line blocked, then that pump
could be suspect. Low power to the pump can cause it too though.
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)
>
> Mike Romain wrote:
> > I would be looking at the connection on the throttle position sensor
> > first. I use a spray contact cleaner on the connections on mine. WD40
> > will work as a connection cleaner too.
> >
> > They are a rheostat and can get a dead spot, but their electrical
> > connection can cause hiccups like you describe too. You can use a
> > multimeter on ohms and take the readings as you open the throttle with
> > it unplugged and the engine off. It should change evenly. If the
> > resistance bumps, you likely have found the trouble.
> >
> > I hear you can clean the guts of the TPS too, but have never needed to.
> >
> > 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)
> >
> Few months ago, Jeep was at authorised workshop and guy hooked it up
> on some kind a multitester for Chrysler/Jeep and complete test passed
> through all of electronic items and found nothing wrong. Guy told me he
> has no time to drive around with "tester thing" so we couldn't see what
> happens when it comes to loaded 2250 rpm.
> Mike, what about this fuel pressure, can it be just a damn pump?
> Logically, when you pinch return hose, pressure should jump very fast,
> right?
I live in the rust belt so usually look for bad connections first. They
are cheap and easy fixes. Our 88's fuel pump is run via a ceramic
ballast resistor that is out on the fender near the rad. That is open
to the elements and gets bad connections now and then.
The ground for the fuel pump is the body and the mesh strap from the
rear of the head to the firewall goes rotten easy not letting a
consistent circuit happen, but that usually causes stalls at speed like
a CPS going bad.
That TPS is known to give an acceleration hiccup though. It is cheap
and easy to clean it's connections just for the heck of it. Mine need a
clean it every two years or so.
I have seen fuel pump impellers come loose on Dodge and Chrysler
vehicles though. The suckers hum and draw power right, but just a
trickle comes out.
If you think you actually got the return line blocked, then that pump
could be suspect. Low power to the pump can cause it too though.
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)