Jeep stalls when giving gas

My '90 Cherokee 4.0 has an annoying problem. It stalls if I stop briefly
and then try to drive off. It runs great all other times, it's only in
this particular situation it acts up. After it stalls, it starts right
up and runs great. The same is true if I stop for a longer period of
time, like for a red light.

I suspect the throttle body might be the problem, but before I do
anything I thought I see if anyone here can confirm my suspicion, or
come with better ideas.

It might not be related, but when I start the engine the rpms often rise
to about 1.5k for 2-3 seconds, sometimes longer, before going back to
normal idle speed. This happens hot or cold.


Ulf

On Dec 16, 1:28 pm, Ulf > wrote:
> My '90 Cherokee 4.0 has an annoying problem. It stalls if I stop briefly
> and then try to drive off. It runs great all other times, it's only in
> this particular situation it acts up. After it stalls, it starts right
> up and runs great. The same is true if I stop for a longer period of
> time, like for a red light.
>
> I suspect the throttle body might be the problem, but before I do
> anything I thought I see if anyone here can confirm my suspicion, or
> come with better ideas.
>
> It might not be related, but when I start the engine the rpms often rise
> to about 1.5k for 2-3 seconds, sometimes longer, before going back to
> normal idle speed. This happens hot or cold.
>
> Ulf

======
======

Check the Idle Air Controll and the EGR for carbon buildup.

do a repost


~:~
MarshMonster
~takes a toke.....~
~:~

"Ulf" > wrote in message
...

> It might not be related, but when I start the engine the rpms often rise
> to about 1.5k for 2-3 seconds, sometimes longer, before going back to
> normal idle speed. This happens hot or cold.
>
>
> Ulf


That's normal.

Check your fuel line pressure into the injectors. Try replacing the fuel
filter(s); they may be plugged. There could be one in the tank too.

Or, maybe the injectors are dirty. Chevron's "Techron" gas additive will fix
that.

they had bigtime issues with the tps and the plug would have to be cut off and
the wires soldered in thenn adjusted using a scan tool, and what u descibed is
exactly what would occur
also consider cleaning throttlebody
the 4.0 never had a egr system from day one to the end of it's run

Marsh Monster wrote:

> On Dec 16, 1:28 pm, Ulf > wrote:
> > My '90 Cherokee 4.0 has an annoying problem. It stalls if I stop briefly
> > and then try to drive off. It runs great all other times, it's only in
> > this particular situation it acts up. After it stalls, it starts right
> > up and runs great. The same is true if I stop for a longer period of
> > time, like for a red light.
> >
> > I suspect the throttle body might be the problem, but before I do
> > anything I thought I see if anyone here can confirm my suspicion, or
> > come with better ideas.
> >
> > It might not be related, but when I start the engine the rpms often rise
> > to about 1.5k for 2-3 seconds, sometimes longer, before going back to
> > normal idle speed. This happens hot or cold.
> >
> > Ulf
>
> ======
> ======
>
> Check the Idle Air Controll and the EGR for carbon buildup.
>
> do a repost
>
> ~:~
> MarshMonster
> ~takes a toke.....~
> ~:~

Ulf wrote:
> My '90 Cherokee 4.0 has an annoying problem. It stalls if I stop briefly
> and then try to drive off. It runs great all other times, it's only in
> this particular situation it acts up. After it stalls, it starts right
> up and runs great. The same is true if I stop for a longer period of
> time, like for a red light.
>
> I suspect the throttle body might be the problem, but before I do
> anything I thought I see if anyone here can confirm my suspicion, or
> come with better ideas.
>
> It might not be related, but when I start the engine the rpms often rise
> to about 1.5k for 2-3 seconds, sometimes longer, before going back to
> normal idle speed. This happens hot or cold.
>
>
> Ulf

The high start up RPM is related.

Your trouble description is exactly the same as our 88 Cherokee would do
when the TPS electrical connection got dirty. This is on the throttle
body. We were told it was a bad TPS back in '98 so I figured I would
just clean the connections first. My clean lasted over two years until
it needed it again and then once every two year or so until we sold it
this fall.

Lots of others have the same issue.

I recommend you use a spray electrical contact cleaner (electronic shops
sell the best stuff) on it with some dielectric grease or even spark
plug boot protector on the plug's seal skirt on 'all' your computer's
electronic sensors, not just the TPS.

The CPS is also a known failure point to the point that DC even
recommend cutting the plug out and soldering the thing in. When it gets
it's bad connection, the engine just up and stops at speed, then will
usually go again for a while.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
'New' frame in the works for '08. Some Canadian Bush Trip and Build
Photos: http://mikeromainjeeptrips.shutterfly.com

I believe the 1990 Renix System TPS can be manually adjusted using a
digital multimeter and a screwdriver, no scan tool needed.

His issue is the TPS connection though. Been there, many times.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
'New' frame in the works for '08. Some Canadian Bush Trip and Build
Photos: http://mikeromainjeeptrips.shutterfly.com

philthy wrote:
> they had bigtime issues with the tps and the plug would have to be cut off and
> the wires soldered in thenn adjusted using a scan tool, and what u descibed is
> exactly what would occur
> also consider cleaning throttlebody
> the 4.0 never had a egr system from day one to the end of it's run
>
> Marsh Monster wrote:
>
>> On Dec 16, 1:28 pm, Ulf > wrote:
>>> My '90 Cherokee 4.0 has an annoying problem. It stalls if I stop briefly
>>> and then try to drive off. It runs great all other times, it's only in
>>> this particular situation it acts up. After it stalls, it starts right
>>> up and runs great. The same is true if I stop for a longer period of
>>> time, like for a red light.
>>>
>>> I suspect the throttle body might be the problem, but before I do
>>> anything I thought I see if anyone here can confirm my suspicion, or
>>> come with better ideas.
>>>
>>> It might not be related, but when I start the engine the rpms often rise
>>> to about 1.5k for 2-3 seconds, sometimes longer, before going back to
>>> normal idle speed. This happens hot or cold.
>>>
>>> Ulf
>> ======
>> ======
>>
>> Check the Idle Air Controll and the EGR for carbon buildup.
>>
>> do a repost
>>
>> ~:~
>> MarshMonster
>> ~takes a toke.....~
>> ~:~
>

Mike Romain wrote:
> Ulf wrote:
>> My '90 Cherokee 4.0 has an annoying problem. It stalls if I stop
>> briefly and then try to drive off. It runs great all other times, it's
>> only in this particular situation it acts up. After it stalls, it
>> starts right up and runs great. The same is true if I stop for a
>> longer period of time, like for a red light.
>>
>> I suspect the throttle body might be the problem, but before I do
>> anything I thought I see if anyone here can confirm my suspicion, or
>> come with better ideas.
>>
>> It might not be related, but when I start the engine the rpms often
>> rise to about 1.5k for 2-3 seconds, sometimes longer, before going
>> back to normal idle speed. This happens hot or cold.
>>
>>
>> Ulf
>
> The high start up RPM is related.
>
> Your trouble description is exactly the same as our 88 Cherokee would do
> when the TPS electrical connection got dirty. This is on the throttle
> body. We were told it was a bad TPS back in '98 so I figured I would
> just clean the connections first. My clean lasted over two years until
> it needed it again and then once every two year or so until we sold it
> this fall.
>
> Lots of others have the same issue.
>
> I recommend you use a spray electrical contact cleaner (electronic shops
> sell the best stuff) on it with some dielectric grease or even spark
> plug boot protector on the plug's seal skirt on 'all' your computer's
> electronic sensors, not just the TPS.
>
> The CPS is also a known failure point to the point that DC even
> recommend cutting the plug out and soldering the thing in. When it gets
> it's bad connection, the engine just up and stops at speed, then will
> usually go again for a while.

Thanks for your excellent reply. I'll try that as soon as I'm able to
get the Jeep started. Issue #2 I have with it is that the battery keeps
going flat when it's not driven for a few days.

BTW, I found the procedure on adjusting the TPS that was mentioned.

http://autorepair.about.com/library/faqs/bl232i.htm

>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 'New' frame in the works for '08. Some Canadian Bush Trip and Build
> Photos: http://mikeromainjeeptrips.shutterfly.com
Ulf

Ulf wrote:
> Mike Romain wrote:
>> Ulf wrote:
>>> My '90 Cherokee 4.0 has an annoying problem. It stalls if I stop
>>> briefly and then try to drive off. It runs great all other times,
>>> it's only in this particular situation it acts up. After it stalls,
>>> it starts right up and runs great. The same is true if I stop for a
>>> longer period of time, like for a red light.
>>>
>>> I suspect the throttle body might be the problem, but before I do
>>> anything I thought I see if anyone here can confirm my suspicion, or
>>> come with better ideas.
>>>
>>> It might not be related, but when I start the engine the rpms often
>>> rise to about 1.5k for 2-3 seconds, sometimes longer, before going
>>> back to normal idle speed. This happens hot or cold.
>>>
>>>
>>> Ulf
>>
>> The high start up RPM is related.
>>
>> Your trouble description is exactly the same as our 88 Cherokee would
>> do when the TPS electrical connection got dirty. This is on the
>> throttle body. We were told it was a bad TPS back in '98 so I figured
>> I would just clean the connections first. My clean lasted over two
>> years until it needed it again and then once every two year or so
>> until we sold it this fall.
>>
>> Lots of others have the same issue.
>>
>> I recommend you use a spray electrical contact cleaner (electronic
>> shops sell the best stuff) on it with some dielectric grease or even
>> spark plug boot protector on the plug's seal skirt on 'all' your
>> computer's electronic sensors, not just the TPS.
>>
>> The CPS is also a known failure point to the point that DC even
>> recommend cutting the plug out and soldering the thing in. When it
>> gets it's bad connection, the engine just up and stops at speed, then
>> will usually go again for a while.
>
> Thanks for your excellent reply. I'll try that as soon as I'm able to
> get the Jeep started. Issue #2 I have with it is that the battery keeps
> going flat when it's not driven for a few days.
>
> BTW, I found the procedure on adjusting the TPS that was mentioned.
>
> http://autorepair.about.com/library/faqs/bl232i.htm
>
>>
>> Mike
>> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
>> 'New' frame in the works for '08. Some Canadian Bush Trip and Build
>> Photos: http://mikeromainjeeptrips.shutterfly.com
> Ulf


WD40 will work in a pinch for cleaning it. The pins are small and the
holes need to be sprayed out. I spray, wait a few seconds for it to
dissolve stuff, then spray again to wash it out.

There is no real reason for them to go out of adjustment, ours never
did. It just gave your symptoms until cleaned. I figured the
adjustment is for the install setup.

Your TPS is different than the one in the link... Yours has a dedicated
adjustment screw under a cap like a carb mix screw cap. There are
voltage readings for the pins with the plug hooked up. The center and
the top are the ones to use. If you have the engine off with the key in
run and the throttle closed, the reading should be about 0.026V, greater
than .02V. Then you go wide open and the voltage should read just under
4.8V. If you have an automatic, one set of wires will also give 4.8V at
closed and .026V at open.

Mike