1989 intermittent rough start and stalling
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Joined: Feb 2009
Posts: 74
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From: Acworth Georgia
Hi DWC4!
As stated in the last post--I cleaned and gapped the plugs--They only have about 7k miles on them. They were really black. Also replaced the O2 sensor--really black as well. I still have a really rich smelling exhaust and a little black soot on the rear bumper just above where the exhaust tips end. Inside of the pipes are black as well. I know it's running rich.
I switched out the Hypertech chip for the original just to see if any difference. Only real difference I can tell is the trans shift points are at a lower RPM spread.
I guess I'm on the right track since the car has been driven quite a bit and hasn't tripped any codes. The last thing to do is buy a new ECM. Chevy dealer has one for about 150.00 with returning the core. I'll probably do that soon. If that doesn't fix the rich condition, I'm not sure what to do then.
Do you know if the ECM can be re-flashed on a model this old?
As stated in the last post--I cleaned and gapped the plugs--They only have about 7k miles on them. They were really black. Also replaced the O2 sensor--really black as well. I still have a really rich smelling exhaust and a little black soot on the rear bumper just above where the exhaust tips end. Inside of the pipes are black as well. I know it's running rich.
I switched out the Hypertech chip for the original just to see if any difference. Only real difference I can tell is the trans shift points are at a lower RPM spread.
I guess I'm on the right track since the car has been driven quite a bit and hasn't tripped any codes. The last thing to do is buy a new ECM. Chevy dealer has one for about 150.00 with returning the core. I'll probably do that soon. If that doesn't fix the rich condition, I'm not sure what to do then.
Do you know if the ECM can be re-flashed on a model this old?
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Joined: Mar 2006
Posts: 523
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From: Golden CO
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Shaybob, you're outa my league on knowledge. I've owned a few vettes, an 85 then my current 92, and I'm still trying to figure things out on it myself. The black box stuff, ECM etc, we can't really sort out without some sophisticated tools, and if that's what you're down to, as a guy with 20 years in the computer industry and for $150, I'd say make the swap. In computers, we swapped parts because no way we could figure out if a 'part' had gone bad without trying a new one to see if it fixed the problem.
Not much help but good luck my friend. I'm interested in your outcome because I'm chasing similar problems, and still deciding what parts to throw at it.
Not much help but good luck my friend. I'm interested in your outcome because I'm chasing similar problems, and still deciding what parts to throw at it.
