Engine won't idle
11-05-2006, 09:42 AM
#1
Racer
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Location: Pasadena Maryland
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Engine won't idle
My neighbor has a 89 L98. Automatic, Stock engine. He just came knocking at my door and asked my if I could help him. His car will start buy it dies after he stops horsing the gas pedal. Just will not idle. It just started to get cold here in Maryland. Could it be some sort of cold start solenoid or the MAF sensor. I have a carburated 78 and I'm not familar with the TPI systems. Hopefully some will chime in and help.
11-05-2006, 11:52 AM
#4
1st Gear
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My idle story
I just recently had that problem. I also have an 89 that would not idle. I went through the normal process MAF,IAC,TPS and I just could not figure it out. I gave up and took it to a guy I know who is an awesome mechanic. The first thing he did was check for a vacuum leaks. He took a gallon jug of water and started pouring it around th throttle body base plate and intake. Yep the throttle body base gasket was shot. I took it apart and the gasket was broken and what was left crumbled in my hand. I knew the intake gasket was old because oil was resting on top. well it also was letting air into the engine. Once they were replaced the engine purred like normal again. The 89 is old and the gasket are too. Anyway thats my story that happened just this week.
11-05-2006, 12:05 PM
#5
Race Director
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Have him test the ECT sensor. When the ECM knows the engine is cold, it commands a cold, fast, idle, just like the choke does on your '78. If the ECT sensor isn't telling the ECM that the engine is cold... no cold idle.
RACE ON!!!
RACE ON!!!
11-05-2006, 02:44 PM
#6
Le Mans Master
There is NO cold start soleniod on the 89 (as Rick stated) nor on the 85-88 vettes that have the CSV system. The post above me about the CTS could be a problem. It is located in the front of the intake manifold (yellow and black wire on my 86). It can be ohm check that will vary with engine temp. Increase temp...decrease (resistance) ohm reading. Decreased temp...increased (resistance) ohm reading.
Also disconnect the MAF and see if there is a difference.
This could be a few different things causing this condition.
Also disconnect the MAF and see if there is a difference.
This could be a few different things causing this condition.
11-05-2006, 04:54 PM
#7
Drifting
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St. Jude Donor '11-'12-'13
Originally Posted by RRT vette
There is NO cold start soleniod on the 89 (as Rick stated) nor on the 85-88 vettes that have the CSV system. The post above me about the CTS could be a problem. It is located in the front of the intake manifold (yellow and black wire on my 86). It can be ohm check that will vary with engine temp. Increase temp...decrease (resistance) ohm reading. Decreased temp...increased (resistance) ohm reading.
Also disconnect the MAF and see if there is a difference.
This could be a few different things causing this condition.
Also disconnect the MAF and see if there is a difference.
This could be a few different things causing this condition.
I disconnected the MAF and it was at least more driveable without dying all the time, that's embarrasing. Replaced MAF, cured that problem, then on to the next. Good luck.
Bryan