1990 blazer stumbling issues

[ethanthatcher777]

My blazer runs fine until it gets warm; then it dies at idle. I've replaced the TPS, ICM, IAC, fuel pump relay. O2 sensor is working according to live data on my Snap-on scanner aswell as the MAP. Fuel pressure is good, has a new fuel pump. The coil is good and strong. When it tries to stall, you can sometimes keep it running; it'll run like its running on 1 cylinder for 4 seconds, then recover, and repeat. If you Let it sit for 10 minutes it'll start idling again but it'll start doing it once you drive. And this just started out of the blue one day when I had to crank my truck over twice because it'd stall once since then it's been downhill.

 

[Fastereddie]

Bad distributor is my guess

 

[Wes Harden]

yeah the pick up coil wiring, starts moving when computer starts adjusting timing. If you go repair the current dist route be sure to check for excessive play in the shaft 1st.

 

[ethanthatcher777]

My blazer runs fine until it gets warm; then it dies at idle. I've replaced the TPS, ICM, IAC, fuel pump relay. O2 sensor is working according to live data on my Snap-on scanner aswell as the MAP. Fuel pressure is good, has a new fuel pump. The coil is good and strong. When it tries to stall, you can sometimes keep it running; it'll run like its running on 1 cylinder for 4 seconds, then recover, and repeat. If you Let it sit for 10 minutes it'll start idling again but it'll start doing it once you drive. And this just started out of the blue one day when I had to crank my truck over twice because it'd stall once since then it's been downhill.

Update ecm was bad

 

[rampage]

Update ecm was bad

Not necessarily. Just simply unplugging the old one and plugging in the new one could have restored a bad connection at connector.

 

[imiceman44]

Not necessarily. Just simply unplugging the old one and plugging in the new one could have restored a bad connection at connector.

I had that happen.
I also had a 1999 where I was having intermittent issues and I looked at the ecm and it was covered with aluminum oxide.
I opened it and the inside was just as bad, not able to find a replacement I spent a few hours cleaning the case and blowing a brushing off the white powder of the circuit board then put it back together and it is working flawlessly.
Four years now

 

[rampage]

I had that happen.
I also had a 1999 where I was having intermittent issues and I looked at the ecm and it was covered with aluminum oxide.
I opened it and the inside was just as bad, not able to find a replacement I spent a few hours cleaning the case and blowing a brushing off the white powder of the circuit board then put it back together and it is working flawlessly.
Four years now

Did you use rubbing alcohol and a toothbrush?

 

[imiceman44]

Did you use rubbing alcohol and a toothbrush?

Contact cleaner and a toothbrush.
It was causing shorts when there was moisture in the air in the winter

 

[ethanthatcher777]

Not necessarily. Just simply unplugging the old one and plugging in the new one could have restored a bad connection at connector.

Possibly but connections weren't corroded and it had a reman one for the previous owner.