Help! '89 just loses power -- will only idle.

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Oct 1, 2005 | 08:38 PM

sammyb

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Burning Brakes

Joined: Oct 1999

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Help! '89 just loses power -- will only idle.

I replaced the intake manifold gasket recently, and ever since, my 1989 Corvette will run decently for a few minutes (and sometimes up to 45 minutes) then totally lose engine power (not electricity -- it will simply just die to an idle...and pushing on the gas doesn't do anything but make it want to totally die.) Sometimes at wide open throttle it cuts out too.

My buddy scanned it for codes and it throws basically every single code in the book!!!

I don't know where to look or what to do. It's almost like there's no fuel being sent. Maybe the ECU is shorting out, or a wire is pinched.

Please any ideas, guesses...anything?!?!?

Thanks in advance!!!
Sam

Last edited by sammyb; Oct 1, 2005 at 10:21 PM.

Oct 1, 2005 | 09:00 PM

bogus

Team Owner

Joined: Aug 2000

Posts: 40,156

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From: San Pedro CA

I would suspect the intake... be sure you don't have a vacuum leak.

Or, a bad wire on the engine harness.

This problem starts and stops with the intake manifold. If nothing else, I would tear into it and make sure all is well

Oct 2, 2005 | 12:25 AM

Great White North

Burning Brakes

Joined: Jul 2004

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From: Langley B.C.

Any chance the TPS got soaked with solvent or degreaser?

Oct 2, 2005 | 12:27 AM

sammyb

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Burning Brakes

Joined: Oct 1999

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Quote:

Originally Posted by bogus

I would suspect the intake... be sure you don't have a vacuum leak.

I'm not sure how a vacuum leak would present like this. The car can run for 45 minutes just fine, and then it dies. I can turn it on the next time and it won't run at all. It seems too random to be a vacuum leak on its own -- at least that's just my guess.

I wonder which wire could have been pinched. Hmm.

Experts out there???

Oct 2, 2005 | 12:29 AM

sammyb

Thread Starter

Burning Brakes

Joined: Oct 1999

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Quote:

Originally Posted by Great White North

Any chance the TPS got soaked with solvent or degreaser?

I suppose it's very possible...But do you think that it would be that twitchy to work sometimes, but not all the time after being in degreaser?

Oct 2, 2005 | 10:52 AM

rick lambert

Le Mans Master

Joined: Oct 2003

Posts: 6,130

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From: seattle WA

I wouldn't think a vacumn leak would cause multiple codes being thrown-I suspect electrical gremlins (PIA). I'd start by checking the connections at the ECM, alternator, starter and bulkhead connection.
Could be a bad wire, connection or the ECM going.BTW, how are the cats?

Oct 2, 2005 | 11:51 AM

Sam Lam

Melting Slicks

Joined: Apr 2002

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From: St. Charles, MO Route 66 Corvette Club

Sam: From your posting it appears that the intake gasket change caused your problem. Question for you: how was it running before the gasket change? Why did you change the gasket?

Have you checked the routing of your vaccum lines and all electrical connections you "opened" during your project? Sounds like you have something hooked up wrong!

The 89 has a lot of problems with Multec injectors, but this problem does not normally throw codes to the ECM.

The wires going to your ECM are located just behind the right side (passenger) valve cover and there is not a bulkhead connector on these wires (at least there is not one on my 89). Make sure you did not damage these wires!
SAM

Oct 2, 2005 | 01:08 PM

sammyb

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Burning Brakes

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I changed the intake gasket because one of the manifold holes stripped out and the gasket failed, pouring coolant everywhere. My wife was driving at the time, but only drove about a mile, so it wouldn't have even had time to really get up to full operating temp.

It drove fine before. It sat in my garage for 6 or 8 months waiting for the intake change.