nickzdad

I have a 1998 Cherokee Sport (XJ) with a 4.0 Liter, all stock. I have recently been experiencing the vehicle stalling, or wanting to stall while I am driving.
It is December in New England so it is cold in the morning.
Along with the stalling, I have noticed that my fuel gauge is also intermittent. The fuel is low in the tank right now in anticipation that a fuel pump might be involved, but the gauge is reading well below the actual level.
I have no codes and the CEL is only on during a stall. I do not know if the light causes the stall or the stall causes the light.
It seems to stall more often when the engine is cold than when it has warmed up but that may be related to speed more than temp.

I have changed the Cat and both O2 sensors but not because of this problem. The problem was occurring before and after the O2 sensor change.

I changed the Crank Position Sensor but the problem persists.
I checked the Fuel Pressure and it is at 49psi.
I had the battery load tested and appears good (700 CCA on a 650 rated battery)
Next on the list is the AIC.

Any help on this will be appreciated. I know that there are a lot of threads about this problem and I have read many. Most end without a solution or have slightly different symptoms. I obviously want this problem solved soon but would also like to post the root cause (once found) for others to reference.

CCKen

Don't know what the term "stall" means. Quit? Stop running?

As for codes and CEL. Take your Jeep to an Advance, O'reilly, etc. parts store and have them scan for 'Pending' codes. The PCM will store diagnostic trouble codes without putting the CEL on.

Get the code(s) and post them, not the generic cause the parts store puke tells you his scanner says.

Later...

nickzdad

CCKen - I use the term "stall" to say stop running as if the ignition was switched off.

I have my own scan tool and there are no codes stored or pending.

CCKen

Hummm...no pending codes.

The CEL won't cause the stall, as you previously asked.

I would suspect the fuel pump but you say you have 49 psi.

"It seems to stall more often when the engine is cold than when it has warmed up but that may be related to speed more than temp."

Could you explain this some more?

98_XJ Sport

Maybe a little bit of help, I know for a fact I need to replace my fuel pump soon because the check valve is shot. The other morning was the first time my Jeep had ever stalled and I'm assuming it was because of the loss of pressure overnight plus the extreme cold temps.

nickzdad

CCKen;

Speed vs Temp may more accurately be stated as THROTTLE POSITION or ENGINE SPEED. I noticed that when I leave work at night driving thru town (20mph) it is more likely to die. Driving to the next town (40-50 mph) it has a better chance of staying running. I also noticed that the CEL appears to come on a fraction of a second after the stalling seems to take place.

I picked up a Cap and rotor and will replace the battery terminals but this is beginning to sound like
1. Bad Duralast CPS
2. Failing throttle position sensor
3. Interrupted spark

XJ - my Cherokee also depletes fuel pressure but it jumps right up to 49 psi when i crank and holds it there so I have ruled out the pump for this problem. It may still need to be replaced but only one headache at a time please

BimmerJeeper

https://www.cherokeeforum.com/f59/no...cklist-155216/

https://www.cherokeeforum.com/f59/to...h-idle-155383/

BimmerJeeper

Non OEM CPS is a common complaint. It's weird how many forum members still buy these despite 100's of threads advising otherwise.

nickzdad

Ok - here is an update.
I swapped out the CPS for another one (still a cheapo)
Determined that no matter how tight I made the positive battery terminal I could still pull it off with my hand. Changed the positive terminal. Added a 6AWG cable from engine block to firewall.
I took this for a short drive and no stalling/bucking and the fuel gauge remained accurate.
Now this was a short trip in the middle of the day so I am not calling this fixed yet. I will wait for a week of total lack of symptoms before I call it done. I am expecting to have to change dist cap and rotor and clean the throttle body for this to be fixed but i will keep you posted.

CCKen

Good fixes and progress.

Let us know how you make out.

Cheers

nickzdad

Less than a week later and I believe that the el-cheapo CPS has crapped out on me. Then engine died on me three times yesterday while driving and refused to start this morning.

More detail: This behavior is slightly different from original. While driving down the road I realized that I no longer had engine power or power steering. The CEL did not come on as it had with the original problem. The fuel gauge remained working and accurate. I would need to allow 2-5 minutes before restarting. This morning, after sitting overnight, it refused to start at all. I removed the newest CPS and re-installed original CPS and engine started right up. I drove straight to the local Jeep stealership and ordered an OEM CPS. I will pick that up tomorrow and install at a later date.

I am confident that I can resolve this problem by throwing lots of parts at it but, while my patience holds out, I am trying to go one step at a time to positively identify the problem. If I do multiple "fixes" at once then I will not know which action was the real repair. Of course I did the battery terminal and the CPS at the same time last weekend so there is still some mystery there, but I plan on allowing time with the original CPS back in the vehicle to determine if indeed the CPS was the problem or the battery terminal was.
I will keep you posted after the holidays.

cptmorgan419

I have a 1998 JGC Laredo 4 ltr. I have also had issues with stalling, I replaced every sensor, the CAT converter, battery. They all worked for a few days then it started all over again. I then replaced the PCM. And have had no problems for over a month now! It is available on eBay and make sure to get one with a lifetime warranty because they are all rebuilt. This helped restore my faith in my jeep. It drives like new. The PCM cost me $150 and that was after $1400 in sensors and other temp fixes. I hope this helps!

BimmerJeeper

I don't understand your logic.
You were having driving issues.
You replaced the CPK.
Still had issues, so you put back the original CPK.
If this was the problem, you should still have driving issues.

Turbo X_J

OP can your scanner capture live data? Failing that you should get a P1391 Intermittent loss of CMP or CKP if not the PCM is not recognizing it. Have you tested the TPS with a DMM and made sure there are not any dead spots?

nickzdad

Bimmer - are you reading the posts or just skimming over them? If you pay attention to what is being discussed you will answer your own question.

Turbo - My scanner will display live data but not with this Jeep. I assumed that this PCM (Power-train Command Module?) did not support this feature (early version of software?). You are referencing the CKP (CranKshaft Position sensor?) and the CMP. Do you mean CaMshaft Position Sensor? I have not looked at the Throttle Position Sensor (TPS) yet. I am attempting to address one item at a time.