Click Here for Instructions on: "HOW TO IDLE-RELEARN"

HOW TO RE-LEARN THE IDLE

If your battery has been disconnected for any reason, you may need to perform this procedure in order for the computer to relearn how to idle. Under most circumstances, it will relearn after just driving the car for a while, but if your car continues to experience an abnormal idle, or you just don't want to wait for it to relearn on its own, you can try this procedure.


STEP ONE:

Disconnect the Negative cable for a few minutes. While The negative cable is dissconnected, pump the brake pedal a few times to clear out any voltage in the system. Re-connect the negative cable after this is complete. Turn off air conditioning controls and all other accessories.

STEP TWO:

Run the engine up to operating temperature and shut off.

STEP THREE:

Apply the parking brake. Start the vehicle and place it in drive (A/T), or neutral (manual).

STEP FOUR:

Run the engine until the cooling fan has cycled on and off, or for a maximum of 10 minutes.

STEP FIVE:

Turn the ignition key off for at least 5 seconds.

STEP SIX:

Restart the engine and again shift into drive or neutral. Allow engine to run for at least 5 minutes.

STEP SEVEN:

Shut off engine for 10 seconds and restart.

STEP EIGHT:

That should do it. With engine stabilized and in closed loop, the IAC motor values should be between nine to 12 counts. If not, the adjustments may be tailored by adjusting the minimum air rate screw. More throttle valve opening equals lower IAC counts. Less throttle opening equals higher IAC counts.

Great info, wish I had this info when I had the problem.

THIS NEEDS TO BE A STICKY!!!!!!!!!!!!!!!!!!


HOW TO RE-LEARN THE IDLE

If your battery has been disconnected for any reason, you may need to perform this procedure in order for the computer to relearn how to idle. Under most circumstances, it will relearn after just driving the car for a while, but if your car continues to experience an abnormal idle, or you just don't want to wait for it to relearn on its own, you can try this procedure.


STEP ONE:

Disconnect the Negative cable for a few minutes. While The negative cable is dissconnected, pump the brake pedal a few times to clear out any voltage in the system. Re-connect the negative cable after this is complete. Turn off air conditioning controls and all other accessories.

STEP TWO:

Run the engine up to operating temperature and shut off.

STEP THREE:

Apply the parking brake. Start the vehicle and place it in drive (A/T), or neutral (manual).

STEP FOUR:

Run the engine until the cooling fan has cycled on and off, or for a maximum of 10 minutes.

STEP FIVE:

Turn the ignition key off for at least 5 seconds.

STEP SIX:

Restart the engine and again shift into drive or neutral. Allow engine to run for at least 5 minutes.

STEP SEVEN:

Shut off engine for 10 seconds and restart.

STEP EIGHT:

That should do it. With engine stabilized and in closed loop, the IAC motor values should be between nine to 12 counts. If not, the adjustments may be tailored by adjusting the minimum air rate screw. More throttle valve opening equals lower IAC counts. Less throttle opening equals higher IAC counts.

That's a good thing to know.

Here's something I found in my Haynes to help provide some more guidance. Instead of typing a long paragraph, I'm going to put into steps.

1. Start the engine and run it as close to idle speed as possible until it reaches its normal operating temperature.
2. Run it for approximately 2 minutes at 1200 RPM.
3. Drive the vehicle as far as necessary, approximately 5 miles of varied driving conditions is usually sufficient to complete the relearning process.

Robert A. Rieke

Can you please tell me how to check the counts of the IAC? for a 92 lumina my lumina jsut started stalling at low speeds and I can figure it out at all.

Thanks for posting this. It's very helpful!

My friend that does performance chips for the 88-94 FWD cars has me do it different on my 91 & 92 Z34 5 speed cars.... Pull ECM fuse for about 30 sec., put it back in, turn key to ON but do not start for 5 sec., turn it off, turn it ON again for 5 seconds but do not start, then start it... So far for the last 3 years I have never had a problem doing it this way.

will the ECU/IAC "learn" over many weeks, or will in never re-adjust, until you do what you are saying to do...

The problem I have, after the car warms up, you can hear, and see on the tach, it doing a periodic "bounce" down from 900 rpm, or whatever it's supossed to be idling at all the time when warm. The car never stalls, because it recovers very quickly, but I didn't know if this was an indication of a failing IAC motor?

The car never does this when given gas... the tach is steady. I have replaced the Ignition Module a year ago, as this did go bad (tach would bounce all over the place at times, and stall the engine when really warm, etc)

How can I Trouble shoot this, or is this a classic sign of a failing IAC motor? It's easy enough to replace, but I don't want to do it, unless it is what is causing the problem for sure. - Again, not bad enough to stall the car... but I hate seeing the tach do that... doesn't idle rough or anything... just does that dipping...

Thanks

If all else fails, go to the gm garage and have the idle reset. aproximately $30, 1/2 hour labor. The only cars that SHOULD need this are early 90's gm's. All current cars SHOULD reset themselves.

how early does a car have to be for this procedure to be necessary?i have a 94 lumi, does it require a manuel idle reset or does it do it itself?
thanks for getting back to me on this in advance.

hey does anybody know what years of lumies this idle reset applies too?

I have learned that cleaning the throttle body before starting up after a battery disconnect helps tremendously !!! No creeping idle...no nothing !
Phil

HOW TO RE-LEARN THE IDLE

STEP TWO:

Run the engine up to operating temperature and shut off.

STEP THREE:



Running the engine up to operating temperature :uhoh:

Do you mean driving (or let run in the neutral) until the fan start ?



Thanks
Guillaume


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Chevrolet Lumina Z34 1991
250 000 KM, second engine
3.4L DOHC DUAL TWIN CAM
5 Speed Manual
Cone Filter & Big Exhaust

This thread is too old, btw in neutral