Hello, This started just before winter. Ran great till warmed up then would backfire and stall but start backup and die or idle very rough when put in gear. Replaced caty as it was rattling. Still had same trouble though. Then cold weather set in and had no problem all winter.
Now spring has arrived and with temps over 65 the problem is back. I replaced the icm about 2 weeks ago. I replaced the icm because every time it happened, I would trickle a little cold water over the heat sink and viola, it would fire up and run great for a little while.As soon as the temp outside hits around 70 the same problem returns. I am leaning towards the ignition coil making the icm overheat. Just thought i would see what the forum has to say.
thanks in advance.

 

Is it doing it right away when you start it or after letting it run for a bit? This may help, it's my Dakota. But it had kind of the same problem. There was actually 2 coolant temp sensors, and I changed one and nothing, then changed the other one after out of ideas and that was the problem.

https://blazerforum.com/forum/showth...ghlight=dakota

http://dodgeforum.com/forum/1st-gen-...then-dies.html

 

Both should be able to be tested although it seems like most folks have a hard time finding an autoparts store that will do it anymore.

Did you clean the heat sink and re-apply the paste?

The PCM coolant temp sensor is located near the thermostat housing. You can test the resistance as the coolant temperature increases.

 

Hi, no it does not do it at all when you first start it.and if the temp is below 70 outside you can drive it forever. When the temp gets to 70 outside or so it starts acting up after about 20 to 30 minutes of driving.
As far as the ICM and heat sink I put a new one on and it came with the packet of paste that I used. As far as the temp sensor. it is running just over half way between the 100 and 210 mark on the temp gauge. Could it still be the temp sensor? What are your thoughts on the coil being the problem?
Thanks for helping me guys.

 

The temp sensor may be telling the computer something different than what your gauge reads. I've heard of the coil overheating, I would start with the coil and temp sensor. Good luck.

 

Well, I put in a new coil,that did not work. So I put a new temp sensor on and still doing the same thing.
Are there two temp sensors? The one i replaced was on the driver side just above the exhaust manifold. Do you have any other ideas on what the problem could be?
Thanks

 

Found a post from swartllk that answered my question about the two temp sensors. So i replaced the the one by the thermostat. still having the problem. So we have a new ICM, coil and temp sensor. I am thinking fuel pump now. Could a bad fuel pump cause these symptoms? I used to have a neighbor that had checked it for me with a pressure gauge or something. He has moved and I have no idea what I need to, or how to test it.
Swartllk you are a test it kind of guy. Can you point me in a direction on what I need tool wise and how to test the fuel pump?
Or is there something else that I should be looking at?
I tell you what - a Blazer is a love hate relationship!!!

 

Read up on this

https://blazerforum.com/forum/tech-articles-diy-29/96-fuel-system-diagnosis-23038/