Tech Support Forum - View Single Post - 1991 chevy s10 blazer 4.3 engine backfires in intake manifold

**Raylo** · 05-30-2008, 01:29 PM

I missed that part about idling OK. Whitetail is correct if it is idling OK probably not the EGR.

Go figure, I finish painting the roof of my truck and take it for a spin and I am getting the same symptoms as when the EGR died 3 years ago. Mine sounds like yours except it'll hardly idle at all. I pulled the Haynes manual and it says my CMFI 4.3 with auto trans has a computer controlled EGR that has a pintle that opens more or less IAW PCM signal. No way to test or visually tell if it is bad. Haynes says it requires "special electronic test gear". Guess I'll have to go find a new one... or perhaps just fashion a plate to block it off.

05-30-2008, 01:29 PM	#7 (permalink)
Raylo TSF Enthusiast Join Date: Feb 2006 Location: Maryland, USA Posts: 521 OS: XP Desktop, Vista HP Notebook, XP Notebook	Re: 1991 chevy s10 blazer 4.3 engine backfires in intake manifold I missed that part about idling OK. Whitetail is correct if it is idling OK probably not the EGR. Go figure, I finish painting the roof of my truck and take it for a spin and I am getting the same symptoms as when the EGR died 3 years ago. Mine sounds like yours except it'll hardly idle at all. I pulled the Haynes manual and it says my CMFI 4.3 with auto trans has a computer controlled EGR that has a pintle that opens more or less IAW PCM signal. No way to test or visually tell if it is bad. Haynes says it requires "special electronic test gear". Guess I'll have to go find a new one... or perhaps just fashion a plate to block it off.