Strange sensor/coil problem

93', HO 4.0, manual, ~150k

Well this past weekend running the Ershim side of the Dusey/Ershim trail. Going in did not have a single problem, coming back out is when it all started. Myself and the trail party coldn't figure out why my jeep started sputtering, then stall, and not start back up until after 10-15 min with the hood up.

The only main condition that I could figure out was when the temp reach 210 on my gauge. Later I figured out if I turned on the heater and craked the hood, I could keep the Temps down to 180. This problem only happens when I was crawling down the trail, at on-road speeds (25-65) the air passing through the vehicle keeps the temps down and I don't need to run the heater or crack the hood.

When it does stall, I loose spark, the fuel pump primes and has good preasure. As soon as the faulty sensor/coil cools down I can start it backup and runs fine util it gets hot again, unless I turn on the heater.

This is the age of some of the main culprit sensors:

CPS - changed many of them (not sure if they were bad, but they were within the warrenty period, so I just got them replaced with new ones), probably only 6 mos old
MAP- 10 mos
Engine Temp- 6 mos
O2 - 1.5 years
coil - 1 year
Distributer - 1 year
Plugs and wires - 1 year

What could it be?

Thanks,
Chuck

Do you have an ignition module? When you get some time I have a multi tester so we can run it til it happens and start testing sensors.

No Ignition module. I still have to check the computer codes, does the computer keep codes in memory? If not then I'll have to try to repeat the symptoms.

The computer should keep the codes untill the battery is disconnected or they are cleared.

Well it tripped again, here are the codes and it's point to the creaded CPS again. Man i need to buy stock in the company that makes these stupid sensors.

Any way, it coded 12, 54, 20 something and then 5 5.

So the book points to the CPS or the other distributer sensor. I have a new CPS from Autozone with a three month warrenty for $50. I figure I can play the warrenty game with the old one and get at least a good trail spare out of it. It seems that the heat is killing them off, when my jeep cools down, it starts right back up, no rough idle.

Any other thoughts or a better source for the CPS's would be great, the dealer wants $90 with no warrenty. I'll be changing it out tomorrow, I'll keep you guys posted. I'm still

cant say much about the sensors but i am thinking you might have a bad fan-clutch...
mike

Maybe, but I'm not overheating, it never gets over 210, even at a slow crawl. Most of the time, in the Fresno heat its around 200, at least by my gauge and new temp sensor. It's really wierd, the jeep will be fine for months, and then summer time and the cps's start dieing left and right, I think I just have a CPS Killer, .