mkotz

I am going to keep this very short since I have spend days reading and hours working on the car.

- Had an issue with high erratic idle
- Changed IAC with new AD Delco IAC. Set pintle to what I thought was 1 1/8 inch but was using a measuring tape which is not easy for that
- Followed procedure to set idle speed. Jumped A and B of the alcl, turned ignition on, waited 30 seconds, pulled iac connector, removed jumper, started car, waited for normal operating temp and adjusted idle screw.
- Initially I could not get rpm to be under 800 so I left it like that.
- After driving for a day the idle rpm decided to come down to 550-600 but when it get this low the car starts searching (jumping up and down) and will eventually stall.
- Also a couple times started it the idle was at 1300+ and would not come down
- Checked for error codes and there are none.

I have also adjusted tps voltage and all seems normal. .54 idle was set and had full swing to WOT. So I have not changed it.

I still have a feeling it is the IAC. I read if the IAC is less then 1 1/16 it will idle high... what are the symptoms if the IAC is above 1 1/8?

When I pulled the original one is was black and pretty much seized... I could barely more the pintle with all my force.

I did not take the TB completely off yet as I was trying to avoid. I just sprayed the **** out of it which I had the screws off so I got it pretty clean.

I am at a loss here guys. I hate to start another thread like this but I think I have read everything.

Billygoatkid

Did you end up fixing or fixing it?

Cliff Harris

An old post brought back from the dead, but the info is still relevant...

The ECM resets the IAC every time the ignition is turned on or off. "Setting" it to some magic number means nothing. That said, if the pintle sticks out too far it will bottom in the bore and break the plastic guides as the IAC is screwed in. That is the only reason it should be set to a maximum length.

I just push the pintle in as far as it will go and install. Turn on ignition. Turn off ignition. Turn on ignition and start the engine. Done.

The pintle is not supposed to turn. If you force it you will break the plastic guides. You can push it in and pull it out (without twisting) but it takes some effort to do that.

VikingTrad3r

that and if his iac was seized he should have taken the 15 minutes to remove the tb and clean the crap out of it as it is probably loaded with carbon and who knows what else. and don't forget the little passageways. clean it all!

anyway....yah old thread.