Ok, I have a 92 cherokee laredo. I have been having a stalling problem for the last month and a half. The car starts fine, runs fine, and then randomly (more during the day after its been sitting in the sun) it will stall out. There is no real pattern to it. No stuttering or struggling, just instantly no power. All my electrical works after it dies (ex. stereo stays on, lights stay on etc.). I pull to a stop, wait a few seconds, 2-3 minutes max, and it starts right back up and runs and drives fine. Now i have replaced the crank position sensor, battery connections, fuel filter, plugs, plug wires, dis. cap, and rotor in an effort to find a short or something. Its my daily driver and I need to be pouring money on other things. My next actions im thinking are to change out the ignition coil, and then look into a cam position sensor. Some one please tell me if im moving in the wrong direction or have ANY CHEAP ideas that this could be. Im open to try out any suggestions, but if it involves alot more money im thinking I will have to sell.
Really appreciate any input.

- Z

 

Hey, I like being cheap myself. So instead of changing out parts check them first. If you don't have the diagnostic equipment go borrow them from the auto parts store. At least that's what I do, you'll save yourself a lot of $ in unnecessary parts.

 

I agree im not a fan of throwing parts at a problem, but everything i replaced was rusted out or chewed up in one way or another so almost justified?

 

Have you tried checking fuel pressure maybe the pump is getting tired

 

Here's a thought:

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The Idle Air Control (IAC) is mounted on the back of the throttle body. (front for 87-90) The valve controls the idle speed of the engine by controlling the amount of air flowing through the air control passage. It consists of a stepper motor that moves a pintle shaped plunger in and out of the air control passage. When the valve plunger is moved in, the air control passage flows more air which raises the idle speed. When the valve plunger is moved out, the air control passage flows less air which lowers the idle speed. Over time and miles, the IAC can get carboned up which can have an adverse affect on idle quality. Cleaning the IAC may restore proper function and is an easy procedure to perform and good preventive maintenance so it is never a bad idea.

CLEANING THE JEEP 4.0 IDLE AIR CONTROL

Remove the air filter cover, associated hoses and the rubber boot that goes from the air filter cover to the throttle body. Remove the IAC with a torx driver (2 bolts; one can be kind of hard to get to)

"Gently" wiggle out the IAC from the throttle body. Gasket on the IAC can be re-used if it is not damaged

Clean the IAC with a spray can of throttle body cleaner; inexpensive and available at any place that sells auto parts. Throttle body cleaner is recommended rather than carburetor cleaner as it is less harsh, safe for throttle body coatings and is best for this task. Use cleaner, a rag and a toothbrush and or Q-Tips. Be gentle; don’t twist or pull on the pintle that protrudes from the IAC as it is fragile and you could damage it.

Thoroughly spray clean and flush where the IAC seats in the throttle body with the same spray cleaner

It is also a good idea to clean the entire throttle body itself, the butterfly valve inside of the throttle body and all associated linkage as long as you have things disassembled

 

IMHO replacing parts on the verge of failure is just being proactive. Fewer things to leave you stranded somewhere.
I have some older classics that I replace certain parts on "just because", even though they still operate properly. "Just because" I'd rather do it in my garage than alongside the road on a random Sunday afternoon cruise.

If I were to make a lunch bet, it'd be on an ignition coil that fails when it warms up. Not uncommon at all. You might check if you have spark immediately after it kills, before it sits long enough to start up again.

 

@ cruiser - Sounds reasonable and ive seen that idea on a few other threads. Ill get at it this weekend

@ Radi - This is what i was leaning towards looking into next. How would i go about checking for spark?

 

I left the dealership in 1992 and bought a towing business. I remember something about high failure rate of coils soon after I got into the towing business. Towed a bunch of Jeeps to the dealer for failed coils. It was a vendor issue but I can't remember who the vendor was. Magnetti Marelli?

 

Toss a spare plug in your glovebox. Next time it dies, pull a plug wire off and attach it to your spare plug, set the shell on something metal (grounded), crank the engine and watch for spark.

 

I had a problem like that. Distributor cap gasket was missing, moisture was the reason.
If

 

Which brings up another pertinent point: get an OEM replacement. While the OEM's may have had a bad run, that's long ago fixed... many of the aftermarket coils still have a high failure rate due to cheap construction.

 

Its bone dry in Nevada so I dont think moistures to blame. Ill swing by ac delco today and grab an extra plug, scince im going there anyway (problems on other cars as well ) The coil heat syncing makes sense because it does only seem to die when its really hot outside or the cars been sitting on. Thanks for the input guys, wish me luck.

 

Good luck!

 

Well it didn't stall once yesterday when i had a friend that would help with checking for spark. Stalls 3 times today and I either get told i dont know what im doing and im going about this problem all wrong, or theres no one there to help. Long story short i still havent been able to test spark. Someone came to me with a possible buyer. If I can atleast get what i paid for it then goodbye xj.