I have an '86 GT V-6. The engine idles at 1500 rpm and will not come down. No computer errors nor any sign of a leak in the EGR valve and tube. I replaced the IAC valve and checked and replaced all vacum lines, no leaks. When the computer is in the diaonagistic mode the idle remains the same. The exhaust converter seems to function properely.
Mike
Update, 10-3-99
Ok sports fans. I found a vacum like in the EGR tube and repaired it. However, I still have a high idle of about 1050 rpms. I plugged all of the vacum ports on the manifold and carb, still high idle. I removed and bench checked all of the senors except for the O2. The O2 switch was new but all carboned up.I cannilabized it from a 4 cylinder but cleaned it up before installing on the V6. So far no computer error codes. Any suggestions?
Mike
Update
[This message has been edited by MIKLAV (edited 10-03-1999).]
88 Fiero
Member posted 09-20-1999 06:46 PM
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Did you ever disconnect your battery...reason is it happened the same thing to me...I was told by Keith of Fiero Motorsports that the computer had to learn the settings again...drive your car around put at least a few miles and idle should go down..also...note that you could adjust the butterfly on the throttle body of the V6 Fiero...this is only if your idle dies all the time or really low...or when it's too high...let me know if your interested in finding it's location....
terryk
Member posted 09-20-1999 09:31 PM
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Will the idle come down if the throttle is physically pushed closed?
If there is truly no vacuum leaks, then the TB could be hanging up.
I would still suspect a vacuum leak.
Try spraying some carb cleaner around all of the vacuum lines where they connect. If the engine stumbles, there is a leak there.
mwbackus
Member posted 09-21-1999 12:06 AM
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Increased idle is normal when the engine is cold, but it should drop to ~900 rpm after sufficient warm up (ie..closed loop). It is possible that operating temperature is not being reached (ie..thermostat not closing, etc.,) and closed loop mode is not being achieved within the time of your observations, although I would tend to agree that a vacuum leak is still very likely.
When installing an IAC valve an "additional" reset of the ECM should done AFTER the engine has reached operating temperature and the vehicle has been driven at ~40 mph for an adequate duration (I usually do this at the side of the road). This will clear any code 24's that usually set due to initial high idle conditions caused by the new IAC.
Mike
WGraffiKs
Junior Member posted 09-21-1999 05:12 PM
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MIKLAV,
When my GT did that, it was the EGR tube (corrugated silver tube from the EGR valve to the intake bottom-side) that had cracked. It's hard to see any cracks there, but if there's a leak, you SHOULD hear it! (I know you said that you already checked that) Do the EGR test with engine running. Lift up un the EGR diapham, the engine should stumble/stall. If that's not it, the butterfly adjustment mentioned earlier by "88 Fiero" might help, but it wouldn't make sense to need adjustment unless something else went awry first. The
