Re: Fuel system troubleshooting recommendations?
 

MattMika wrote:
> On Mon, 25 Jun 2007 19:30:46 +0200, "Odd-Inge Larsen"
> <oddingelarsen@dcpost.no> wrote:

ref: (93 cherokee 4.0)

>> Why do you think it's a fuel related problem? Could be, but...
>
> I thought it was fuel system related because the 'cut out' is similar
> to running out of gas. It starts to sputter then gets no power at all.
> Then suddenly it starts running again.

Second CPS.

Fuel filter will show up as a power sag at full throttle (or even light ping)
Fuel cutout will give you a bit of hiccup but the engine usually keeps on
chugging along. If the fuel pump stops it generally stops, period.

>> What came to my mind was also a faulty CPS. When it gets hot it stops
>> working, then cools down and works again. Could of course also be
>> fuel related, ignition related, computer related etc...
>
> Based on the seemingly high rate of failure of these devices it seems
> that will be a good place to start. I see that early 90's models may
> have problems with a low signal strength "due to a larger than desired
> distance to the flywheel sensing ring."
>
> http://autorepair.about.com/cs/faqs/l/bl557h.htm
>
> I guess I'll see how well its position and move it closer if possible
> or replace it and the grommet if it doesnt look like the updated type.

The new ones come with a single hole, the old paper gasket type are no
longer produced.

I have a writeup on the 93ZJ on my website.
http://revbeergoggles.com/cps/
and
http://revbeergoggles.com/Fixes/diag...tml#CPSdetails


--
-- DougW -- 93 ZJ 4.0 http://revbeergoggles.com
HESCO Supercharger - 300W IASCA Stereo - Edelbrock IAS Shocks
Gibson Exhaust - rear DCpower - custom gauge install - Stillen Rotors
Banks Header - and BEER, in the fridge!

Re: Fuel system troubleshooting recommendations?
 

MattMika wrote:
> On Mon, 25 Jun 2007 19:30:46 +0200, "Odd-Inge Larsen"
> <oddingelarsen@dcpost.no> wrote:

ref: (93 cherokee 4.0)

>> Why do you think it's a fuel related problem? Could be, but...
>
> I thought it was fuel system related because the 'cut out' is similar
> to running out of gas. It starts to sputter then gets no power at all.
> Then suddenly it starts running again.

Second CPS.

Fuel filter will show up as a power sag at full throttle (or even light ping)
Fuel cutout will give you a bit of hiccup but the engine usually keeps on
chugging along. If the fuel pump stops it generally stops, period.

>> What came to my mind was also a faulty CPS. When it gets hot it stops
>> working, then cools down and works again. Could of course also be
>> fuel related, ignition related, computer related etc...
>
> Based on the seemingly high rate of failure of these devices it seems
> that will be a good place to start. I see that early 90's models may
> have problems with a low signal strength "due to a larger than desired
> distance to the flywheel sensing ring."
>
> http://autorepair.about.com/cs/faqs/l/bl557h.htm
>
> I guess I'll see how well its position and move it closer if possible
> or replace it and the grommet if it doesnt look like the updated type.

The new ones come with a single hole, the old paper gasket type are no
longer produced.

I have a writeup on the 93ZJ on my website.
http://revbeergoggles.com/cps/
and
http://revbeergoggles.com/Fixes/diag...tml#CPSdetails


--
-- DougW -- 93 ZJ 4.0 http://revbeergoggles.com
HESCO Supercharger - 300W IASCA Stereo - Edelbrock IAS Shocks
Gibson Exhaust - rear DCpower - custom gauge install - Stillen Rotors
Banks Header - and BEER, in the fridge!

Re: Fuel system troubleshooting recommendations?
 

MattMika wrote:
> On Mon, 25 Jun 2007 19:30:46 +0200, "Odd-Inge Larsen"
> <oddingelarsen@dcpost.no> wrote:

ref: (93 cherokee 4.0)

>> Why do you think it's a fuel related problem? Could be, but...
>
> I thought it was fuel system related because the 'cut out' is similar
> to running out of gas. It starts to sputter then gets no power at all.
> Then suddenly it starts running again.

Second CPS.

Fuel filter will show up as a power sag at full throttle (or even light ping)
Fuel cutout will give you a bit of hiccup but the engine usually keeps on
chugging along. If the fuel pump stops it generally stops, period.

>> What came to my mind was also a faulty CPS. When it gets hot it stops
>> working, then cools down and works again. Could of course also be
>> fuel related, ignition related, computer related etc...
>
> Based on the seemingly high rate of failure of these devices it seems
> that will be a good place to start. I see that early 90's models may
> have problems with a low signal strength "due to a larger than desired
> distance to the flywheel sensing ring."
>
> http://autorepair.about.com/cs/faqs/l/bl557h.htm
>
> I guess I'll see how well its position and move it closer if possible
> or replace it and the grommet if it doesnt look like the updated type.

The new ones come with a single hole, the old paper gasket type are no
longer produced.

I have a writeup on the 93ZJ on my website.
http://revbeergoggles.com/cps/
and
http://revbeergoggles.com/Fixes/diag...tml#CPSdetails


--
-- DougW -- 93 ZJ 4.0 http://revbeergoggles.com
HESCO Supercharger - 300W IASCA Stereo - Edelbrock IAS Shocks
Gibson Exhaust - rear DCpower - custom gauge install - Stillen Rotors
Banks Header - and BEER, in the fridge!

Re: Fuel system troubleshooting recommendations?
 

On Mon, 25 Jun 2007, MattMika wrote:

> About a month ago I first experienced some problem with the fuel
> system on my '93 Cherokee(4.0L, 128K).
>
> Usually when it happens I am driving down the road and the fuel seems
> to just cut out for a second or two, but comes right back. On two
> occasions now it has cut out and wont start for a couple minutes, then
> all of a sudden it starts getting fuel again and runs fine.
>
> I'm thinking, at the very least, I need to replace the fuel filter. I
> havent yet looked in my repair manual, but did a brief search online.
> Do I have to pull the whole fuel tank to get to the filter?
>
> Anyone got any insight to what this problem might be?

My `89 Cherokee 4.0L did something that _sounds_ similar. I replaced the
fuel filter and it seemed to clear it up -- until it flat-out died on a
holiday weekend 6 miles from home in the middle of a neighborhood that
looks a lot like Ramadi. The in-tank fuel pump needed replacing and when
they did they had to wash a lot of crap out of the tank. Unfortunately,
they didn't replace the fuel sender, so I kept running out of gas with
about a 1/4 tank left and it had to go back to the shop for that. I don't
know that that is what is happening to you, but if it is you might
consider replacing the pump and sender while the tank is out.

IIRC, there have also been grounding issues with the fuel pump. Someone
with better notes on that should pipe up and guide you on that one.





--
"We began to realize, as we plowed on with the destruction of New Jersey,
that the extent of our American lunatic fringe had been underestimated."
Orson Wells on the reaction to the _War Of The Worlds_ broadcast.

Re: Fuel system troubleshooting recommendations?
 

On Mon, 25 Jun 2007, MattMika wrote:

> About a month ago I first experienced some problem with the fuel
> system on my '93 Cherokee(4.0L, 128K).
>
> Usually when it happens I am driving down the road and the fuel seems
> to just cut out for a second or two, but comes right back. On two
> occasions now it has cut out and wont start for a couple minutes, then
> all of a sudden it starts getting fuel again and runs fine.
>
> I'm thinking, at the very least, I need to replace the fuel filter. I
> havent yet looked in my repair manual, but did a brief search online.
> Do I have to pull the whole fuel tank to get to the filter?
>
> Anyone got any insight to what this problem might be?

My `89 Cherokee 4.0L did something that _sounds_ similar. I replaced the
fuel filter and it seemed to clear it up -- until it flat-out died on a
holiday weekend 6 miles from home in the middle of a neighborhood that
looks a lot like Ramadi. The in-tank fuel pump needed replacing and when
they did they had to wash a lot of crap out of the tank. Unfortunately,
they didn't replace the fuel sender, so I kept running out of gas with
about a 1/4 tank left and it had to go back to the shop for that. I don't
know that that is what is happening to you, but if it is you might
consider replacing the pump and sender while the tank is out.

IIRC, there have also been grounding issues with the fuel pump. Someone
with better notes on that should pipe up and guide you on that one.





--
"We began to realize, as we plowed on with the destruction of New Jersey,
that the extent of our American lunatic fringe had been underestimated."
Orson Wells on the reaction to the _War Of The Worlds_ broadcast.

Re: Fuel system troubleshooting recommendations?
 

On Mon, 25 Jun 2007, MattMika wrote:

> About a month ago I first experienced some problem with the fuel
> system on my '93 Cherokee(4.0L, 128K).
>
> Usually when it happens I am driving down the road and the fuel seems
> to just cut out for a second or two, but comes right back. On two
> occasions now it has cut out and wont start for a couple minutes, then
> all of a sudden it starts getting fuel again and runs fine.
>
> I'm thinking, at the very least, I need to replace the fuel filter. I
> havent yet looked in my repair manual, but did a brief search online.
> Do I have to pull the whole fuel tank to get to the filter?
>
> Anyone got any insight to what this problem might be?

My `89 Cherokee 4.0L did something that _sounds_ similar. I replaced the
fuel filter and it seemed to clear it up -- until it flat-out died on a
holiday weekend 6 miles from home in the middle of a neighborhood that
looks a lot like Ramadi. The in-tank fuel pump needed replacing and when
they did they had to wash a lot of crap out of the tank. Unfortunately,
they didn't replace the fuel sender, so I kept running out of gas with
about a 1/4 tank left and it had to go back to the shop for that. I don't
know that that is what is happening to you, but if it is you might
consider replacing the pump and sender while the tank is out.

IIRC, there have also been grounding issues with the fuel pump. Someone
with better notes on that should pipe up and guide you on that one.





--
"We began to realize, as we plowed on with the destruction of New Jersey,
that the extent of our American lunatic fringe had been underestimated."
Orson Wells on the reaction to the _War Of The Worlds_ broadcast.

Re: Fuel system troubleshooting recommendations?
 

On Mon, 25 Jun 2007, MattMika wrote:

> About a month ago I first experienced some problem with the fuel
> system on my '93 Cherokee(4.0L, 128K).
>
> Usually when it happens I am driving down the road and the fuel seems
> to just cut out for a second or two, but comes right back. On two
> occasions now it has cut out and wont start for a couple minutes, then
> all of a sudden it starts getting fuel again and runs fine.
>
> I'm thinking, at the very least, I need to replace the fuel filter. I
> havent yet looked in my repair manual, but did a brief search online.
> Do I have to pull the whole fuel tank to get to the filter?
>
> Anyone got any insight to what this problem might be?

My `89 Cherokee 4.0L did something that _sounds_ similar. I replaced the
fuel filter and it seemed to clear it up -- until it flat-out died on a
holiday weekend 6 miles from home in the middle of a neighborhood that
looks a lot like Ramadi. The in-tank fuel pump needed replacing and when
they did they had to wash a lot of crap out of the tank. Unfortunately,
they didn't replace the fuel sender, so I kept running out of gas with
about a 1/4 tank left and it had to go back to the shop for that. I don't
know that that is what is happening to you, but if it is you might
consider replacing the pump and sender while the tank is out.

IIRC, there have also been grounding issues with the fuel pump. Someone
with better notes on that should pipe up and guide you on that one.





--
"We began to realize, as we plowed on with the destruction of New Jersey,
that the extent of our American lunatic fringe had been underestimated."
Orson Wells on the reaction to the _War Of The Worlds_ broadcast.

Re: Fuel system troubleshooting recommendations?
 

Before I posted I was thinking heat might have something to do with
it, as the problem started when it started gettingwarm here in Denver.
Today its in the upper 90's and when I went for lunch I drove about 10
mins. and it started acting up. Luckily I was able to get out of
traffic before it totally died. I let it sit while I ate my lunch and
it started right up after a 10-15 min rest.

I checked with Autozone online, they have the part for $61.99, havent
checked if a location close to me has one in stock yet.

I also called Lithia, the jeep dealer by my house, and they said
$127.07. Thats quite a difference.

Are aftermarket CPS's ok or should I stick with OEM?

TIA
Matt Mika

Re: Fuel system troubleshooting recommendations?
 

Before I posted I was thinking heat might have something to do with
it, as the problem started when it started gettingwarm here in Denver.
Today its in the upper 90's and when I went for lunch I drove about 10
mins. and it started acting up. Luckily I was able to get out of
traffic before it totally died. I let it sit while I ate my lunch and
it started right up after a 10-15 min rest.

I checked with Autozone online, they have the part for $61.99, havent
checked if a location close to me has one in stock yet.

I also called Lithia, the jeep dealer by my house, and they said
$127.07. Thats quite a difference.

Are aftermarket CPS's ok or should I stick with OEM?

TIA
Matt Mika

Re: Fuel system troubleshooting recommendations?
 

Before I posted I was thinking heat might have something to do with
it, as the problem started when it started gettingwarm here in Denver.
Today its in the upper 90's and when I went for lunch I drove about 10
mins. and it started acting up. Luckily I was able to get out of
traffic before it totally died. I let it sit while I ate my lunch and
it started right up after a 10-15 min rest.

I checked with Autozone online, they have the part for $61.99, havent
checked if a location close to me has one in stock yet.

I also called Lithia, the jeep dealer by my house, and they said
$127.07. Thats quite a difference.

Are aftermarket CPS's ok or should I stick with OEM?

TIA
Matt Mika