C4 Tech/Performance L98 Corvette and LT1 Corvette Technical Info, Internal Engine, External Engine

Won't Idle When Cold

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Old 09-05-2008, 07:51 AM
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Bob88vette
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Default Won't Idle When Cold

My all stock '88 has just started to die when cold. Pull up to an intersection let off the gas and engine dies. It has no trouble starting right back up and starts perfectly from sitting cold.

After the oil and water heat up good I get a very nice running engine with a 700 rpm idle.

About 5 months ago I had all injectors replaced and fuel rails cleaned. This no idle problem just started a month ago so I don't THINK it's related to that repair.

Where should I start to troubleshoot?

I searched and found alot of idle discussions but none that matched my situation so my apologies if this is a dup.

Thanks as always for the education
Old 09-05-2008, 10:54 AM
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Midnight 85
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My '85 was doing something similar, it would start right up but would die while idling or die when I put it in gear. This would happen until the temp got to about 130. Quite by accident I cured it by swapping MAF sensors. I'm not saying for you to go out and buy a new MAF but if you have a buddy with a good one swap it to your engine and see what happens. My engine threw no codes and the MAF was completely intact inside.
Old 09-05-2008, 11:29 AM
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theadmiral94
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Have you been able to smell the exhaust when it dies (smell gas)?

Is it dieing because it is too rich or lean?

Does your year have an 'IAC' (Idle Air Control) mounted in/on the MAF?

If so, maybe the IAC has failed or its passageways are clogged or it just needs to be reset.

On our 94, there is a reset procedure for the IAC, presume if your year has an IAC, there is a reset procedure for yours too, so you could try it.
Old 09-05-2008, 12:56 PM
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Originally Posted by theadmiral94
Have you been able to smell the exhaust when it dies (smell gas)?

Is it dieing because it is too rich or lean?

Does your year have an 'IAC' (Idle Air Control) mounted in/on the MAF?

If so, maybe the IAC has failed or its passageways are clogged or it just needs to be reset.

On our 94, there is a reset procedure for the IAC, presume if your year has an IAC, there is a reset procedure for yours too, so you could try it.
Old 09-05-2008, 01:55 PM
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MK 82
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Originally Posted by Road Agent

You beat me to it. Someone isn't quite ready for prime time.
Old 09-05-2008, 01:59 PM
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MK 82
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I would start by thoroughly cleaning the TB and the IAC with TB cleaner. Cheap and it probably could use it.





Originally Posted by Bob88vette
My all stock '88 has just started to die when cold. Pull up to an intersection let off the gas and engine dies. It has no trouble starting right back up and starts perfectly from sitting cold.

After the oil and water heat up good I get a very nice running engine with a 700 rpm idle.

About 5 months ago I had all injectors replaced and fuel rails cleaned. This no idle problem just started a month ago so I don't THINK it's related to that repair.

Where should I start to troubleshoot?

I searched and found alot of idle discussions but none that matched my situation so my apologies if this is a dup.

Thanks as always for the education
Old 09-05-2008, 04:05 PM
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65Z01
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I would start by thoroughly cleaning the TB and the IAC with TB cleaner. Cheap and it probably could use it.

And the reset base idle and trim up the TB low/hi adjustments.

If that doesn't solve the problem, pull the connector to the cold start injector and note the effect if any.

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