What did I do? 92 Lt-1
Thread Starter
Instructor
Joined: May 2005
Posts: 125
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From: Avon Park Fla
What did I do? 92 Lt-1
I pulled and cleaned my throttle body,
And the IAC valve. Replaced the
brittle connector on my MAP sensor.
Did the cleaning just like the write
up stated. Now I have a 1500-2200
idle rpm. Please help
And the IAC valve. Replaced the
brittle connector on my MAP sensor.
Did the cleaning just like the write
up stated. Now I have a 1500-2200
idle rpm. Please help
Thread Starter
Instructor
Joined: May 2005
Posts: 125
Likes: 0
From: Avon Park Fla
Checked it, It even has a little slack and
hits the throttle stop no problem.
I was reading VADERs write up on
adjusting idle speed. I dont think that
applies to a 92. I may be wrong
hits the throttle stop no problem.
I was reading VADERs write up on
adjusting idle speed. I dont think that
applies to a 92. I may be wrong
Le Mans Master
Joined: Feb 2006
Posts: 8,753
Likes: 9
From: Louisiana
If the ECM is getting values out of it's range, it will set the code. It could be a few things causing it. Try and feel the IAC when the engine is running. You should feel "ticks" with your finger. It's possible that the IAC is not closing the air passage to bring the idle down.
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Thread Starter
Instructor
Joined: May 2005
Posts: 125
Likes: 0
From: Avon Park Fla
Ok I will try that. I have read a lot
of different ideas and I kick myself
for not having the FSM. What is the
proper way to reset the IAC valve
on a 92, or does it not have to
be reset?
of different ideas and I kick myself
for not having the FSM. What is the
proper way to reset the IAC valve
on a 92, or does it not have to
be reset?
Le Mans Master
Joined: Feb 2006
Posts: 8,753
Likes: 9
From: Louisiana
Again, I don't have refrence for the 92, but reseting the IAC should be explained on vader86's website. The idle speed is burnt into the chip. The IAC is there to control the idle by the ECM moving the pintle in and out according to what info it receives from various sensors/temperature. As far as I know, you will need to put the ECM in diagnostic mode to let the IAC extend all the way to close the air passage. Then disconnect the IAC connector and take the ECM out of diagnostic mode. Start the engine. Now on the 85-89 vettes you can adjust the TPS, but not on yours. Perhaps someone else can shed some light.
Team Owner
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From: Fort Knox, KY
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Did you replace the IAC motor gasket with either a new one or one made from a sheet of gasket paper like I did? You should have put a drop of motor oil on the IAC motor gasket before bolting it back to the TB.
If you have a leak around the IAC motor, or other vacuum leak, it'll cause the high idle you're describing.
If you have a leak around the IAC motor, or other vacuum leak, it'll cause the high idle you're describing.
Thread Starter
Instructor
Joined: May 2005
Posts: 125
Likes: 0
From: Avon Park Fla
Cleaned the motor with a toothbrush and some
throttle body cleaner. Put a drop of oil on the
shaft and used some gasket maker to seal it.
Checking around for a vacumme leak, nothing found
so far.
throttle body cleaner. Put a drop of oil on the
shaft and used some gasket maker to seal it.
Checking around for a vacumme leak, nothing found
so far.
Thread Starter
Instructor
Joined: May 2005
Posts: 125
Likes: 0
From: Avon Park Fla
OK I pulled off the IAC again, I ordered
a new one last night anyway, the pintle,
spring and shaft, I pulled it out of the IAC.
Put some gasket maker on to make a gasket
for a good seal, disconected the batery
for 10 min. Still a high idle???? I dont have
any propane or starter fluid, but I cannot
see any broken or loose vacumme lines.
It has to be something I did. Does anybody
know what size socket the IAC valve takes?
a new one last night anyway, the pintle,
spring and shaft, I pulled it out of the IAC.
Put some gasket maker on to make a gasket
for a good seal, disconected the batery
for 10 min. Still a high idle???? I dont have
any propane or starter fluid, but I cannot
see any broken or loose vacumme lines.
It has to be something I did. Does anybody
know what size socket the IAC valve takes?
Thread Starter
Instructor
Joined: May 2005
Posts: 125
Likes: 0
From: Avon Park Fla
Obatined some starter fluid, I have never
used this to find a vacumme leak.
I sprayed under the throttle body,
and the car acted like it was choking.
I had the inlet duct off [speed density
system] So I take it the bottom gasket
on the throttle body is leaking???
used this to find a vacumme leak.
I sprayed under the throttle body,
and the car acted like it was choking.
I had the inlet duct off [speed density
system] So I take it the bottom gasket
on the throttle body is leaking???