hello all. i have a 2001 LT 4d push button 4x4 auto. in the past month i have replaced the fuel pump, fuel filter, air filter, ignition cap and rotor, spark plugs and wires. in the morning it starts and runs fine. after i drive it for about 15 minutes it starts to lose throttle response and then dies. will not start again untill it sits for a few minutes. after it starts back up it runs fine until i get a few more miles down the road then it does it all over again. I took it to aamco and all they could tell me is their machine says its misfiring like crazy and suggested i replace cap and rotor. I did as they suggested and still having same problem. I also used Bosch Plat. 2 plugs. I've heard this could possibly be the problem. Any ideas?

 

Have the ignition control module checked.

 

So long as those plugs are fairly new, I doubt they are the problem. It sure sounds like either an ICM or coil problem that is affected by heat. When there are problems with either of these two items, they can heat up much more than typical engine temps during operation and cause symptoms such as this. Have them both tested.

 

Thank you both for your input. I couldn't find anyone around here that could test the ICM. I took a mulimeter to it and its getting good juice and ground when both running and when it dies and the key is forward. I then chcked the coil and it is getting spark input and output when it's running, but not after it dies and i try to turn it over again. Would this be the coil or the ICM? Gonna probably hit up the junk yard in the morning and see if i can just get them both at a decent price and see what happens when i change one or the other.

 

i swear i have no luck. I called every salvage yard i could find within a reasonable distance around here, and noe of them have an S-10 or Blazer!!! So i broke down and bought a new ICM..... still the same problem, and since its an electic component i cant return it. Now i alson have a new coil to put in as soon as the rain stops

 

Here in NY Blazers are common in junk yards, of course so is salt in the winter. Based on your observation the coil didn't have any power on the input wires when it dies, I would've voted for the ICM. But I've seen bad coils that run for 10 minute bursts too.

 

new coil now installed-same damn problem. running out of money and ideas....

pulled the EGR, alittle carbon but seems fine. Plunger works smoothly

 

Remove the o2 sensor before the catalytic converter... my guess its clogged..

 

I'm home and don't the schematic in front of me. The same fuse supplies a constant 12v to both the coil and the ICM. The ICM controls the ground to the coil to cycle it on & off. What I don't remember is whether that fuse is ENG1 or ECM1. Check to see if the fuse looks corroded and it has a nice tight fit?

 

Pulled EGR again and cleaned it and the ports good with carb cleaner- idles a little better but problem persists. Pulled O2amd seems fine. Fuses in great shape. Finally got a code thrown and SES light. Says it's the shift selenoid B CKT Performance or Stuck Off. Would that be causing the problem or just a coincidence and more money I'm gonna have to put into the tranny soon?