i have a chevy s-10 blazer. when the weather warms up my truck will stall. let it sit and starts right back up and dose that over and over. never in the winter will it do that.

now what have i changed you ask? what havent i. coil, the whole distribut, fuel pump 2yrs ago,crank sensor,fuel filter, plugs and wires. no codes come up when this happens. i am so at my ends wits dont know what to do anymore. PLEASE HELP ME!!!!!

 

ICM (ignition control module)? This would definitely be affected by heat. You can pull it off of the mounting flange and see if it still has good dielectric grease behind it. If there is none or its all dried up, you should first try cleaning both parts very well, then reapplying the dielectric grease. If that doesn't work, then the ICM can be tested, but most autoparts stores have "lost" the experience/tools necessary to test them properly and just play dumb.

 

thank you for your response. i got an ICM with the new dis. do you think it still could be it? got it less than a year ago. people tellin me could be the fuel pressure regulator. what you think?

 

It still could be the ICM, especially if you didn't use the grease it came with which is there to pull heat away from the ICM and into the bracket/heat sink.

A quick fuel pressure test would let you know if it was a problem with the fuel system.

A partially clogged catalytic converter can cause symptoms like this as well, but typically they don't take so long to come in.

 

thank you for the help. fuel pressure is fine. there really is know way to check cat. is there other than replacing it.? also i will check ICM and put the grease on it. also is stalls almost in the excact same spot every time. well within 30 40 feet. and only when its warm out never in the winter. also it wont do it if the truck just sits there and runs. will run all day and never stall drive is 15 20 miles is quits and wont start till it almost cools right off. going to be spendin all day today and all day sat. to try and get it to stop doing that. will have my computer with me so please any more suggestions send them right away.

 

1996 Chevy S10 Blazer 4X4

First of all I am not a mechanic, so I hope I can help.

This is what I think about the hot stalling problem. If you have checked fuel pressure and it's good, the fuel pump is probably OK. Then check the fuel pump relay, when you turn the key to "on" not start, the fuel pump will run for a couple of seconds. Someone else might have to turn the key to hear it. My intake manifold popped so I had to take off the whole top of the engine. While there I replaced the fuel regulator under the intake manifold plenum.
Last year when this started, I was driving on the first hot day and the car wouldn’t start at the store. So I got a rag and wet it and cooled down the ICM. The car started, so I bought a replacement. After the ICM replacement I was able to drive to Tucson and back during 110° days both ways.
Then after I got home, it would not start again after going to the store. I got stuck and had to be towed home, where it started fine again.
So this year after the car stalled so I did this:
I got an old scrap heat sink from something. I trimmed it to the same size as the original. Using the original holes as a template I drilled matching holes in the scrap heat sink. Using new long bolts and nuts I assembled ICM/silver paste/stock heat sink facing out/silver paste/scrap heat sink facing out the other way/U bracket.

Using a piece of aluminum sheet, I made a "serif" U bracket that matched the coil mount bracket and mounted the assembly on the old bracket. The silver paste is used to thermally connect a CPU or chip to a heat sink.
I have a thought about hot fuel.
The fuel runs on a loop from the tank to the injector, demand opens the fuel regulator, and unused fuel goes back into the tank.
I bought a scan tool that connects to my laptop and watched it while driving around. On an 80° day the intake air temp was 185°!!! The tool only went to 140°.
So I checked the airbox, under the air filter. The snoot coming out of there was not getting any fresh air, it was only ½ from the front wall with no vent holes, so I removed the snoot. The temperature dropped to 100° and the car has not failed since on three 110° days. I did not modify the airbox. I also keep the tank mostly full to cool the fuel pump (that’s why it’s in the tank).
**So I thought that the fuel in the tank was getting heated by the engine, returned hot fuel right next to the fuel pump causing the pump to go too low (overheating). The hot air caused a super vapor lock. So I put a fiberglass shield under the fuel line on the engine.**
Car starts now.

 

wow that's tough! i have the opposite! my truck runs great after it warms up but cant get out of its own way when its cold! then again i live in Miami!..good luck! if i see anything that relates? ill let you know! shane4u