Tech Support Forum - View Single Post - [SOLVED] 95 Chevy S-10 4.3L TBI

**Raylo** · 09-06-2007, 04:39 AM

Interesting thread. I have been reading it even though I have a 1994 S10 p/u with engine code W (CPI) that has a different fuel injector system.

But I did have a similar problem once upon a time. Turned out to be a sticking EGR valve. I replaced it and all has been good. When it happened it was very hard to keep the truck running because dumping a large amount of exhaust gas into the small idle air flow is obviously bad. I saw you replaced the EGR but it might still be worth doing a test by visually verifying that it is shut then removing the vacuum source to make sure it doesn't open when you start the engine.

The other time I had a similar problem was on my Z28 when the air intake elbow came loose on one edge where it attaches to the throttle body allowing a lot of unmetered air into the motor, which reduced air flow over the MAF and totally threw off the computer and mixture.

Anyway, these are a couple of "simple" things to look at. I'm not sayng your trek down the bad PCM path is wrong, it's just that in my experience 99% of the time it turns ot to be something simple.

Good luck. I'll keep reading and hope to see you get this resolved soon.

09-06-2007, 04:39 AM	#12 (permalink)
Raylo TSF Enthusiast Join Date: Feb 2006 Location: Maryland, USA Posts: 521 OS: XP Desktop, Vista HP Notebook, XP Notebook	Re: 95 Chevy S-10 4.3L TBI - Idle troubles Interesting thread. I have been reading it even though I have a 1994 S10 p/u with engine code W (CPI) that has a different fuel injector system. But I did have a similar problem once upon a time. Turned out to be a sticking EGR valve. I replaced it and all has been good. When it happened it was very hard to keep the truck running because dumping a large amount of exhaust gas into the small idle air flow is obviously bad. I saw you replaced the EGR but it might still be worth doing a test by visually verifying that it is shut then removing the vacuum source to make sure it doesn't open when you start the engine. The other time I had a similar problem was on my Z28 when the air intake elbow came loose on one edge where it attaches to the throttle body allowing a lot of unmetered air into the motor, which reduced air flow over the MAF and totally threw off the computer and mixture. Anyway, these are a couple of "simple" things to look at. I'm not sayng your trek down the bad PCM path is wrong, it's just that in my experience 99% of the time it turns ot to be something simple. Good luck. I'll keep reading and hope to see you get this resolved soon.