IAC setting without the ALCL plug?

[22lbChevelle]

Hey I need to set my IAC but I dont have the ACLC plug under the dash. I've just spliced stuff into the C437 plug near the ECM and Im wondering what plugs to cross in the C437 plug in order to satisfy the IAC reset procedure in this link: IAC Reset Procedure



From these charts I think I need to cross the M and E plugs, which is really just grounding the E plug. Is this correct?

 

[22lbChevelle]

Sorry I meant the ALDL plug, still havent figured this one out..

 

[TurboBob]

the factory IAC procedure is not usually used by the group any longer.

the method that has been adopted is to adjust the throttle stop so that the IAC counts are around 10 or so, when the engine is idling in park, warm, with the A/C off.

when adjusting the throttle stop, the TPS setting changes, and needs to be reset. When these changes are made the engine needs to be shut off and restarted so the new TPS setting takes effect in the ECM.

I'm not sure I explained it clearly, but you just tweak the idle stop screw, readjust the TPS, and see what the idling IAC counts settle to.

Bob

 

[22lbChevelle]

Thanks Ill try it and let ya know. Maybe its a bad IAC

 

[TurboBob]

if the tps setting is wrong (too high at idle), the IAC will not control idle speed.

if the throttle blade is not closing far enough or there is a vacuum leak, the IAC reading will go to 0 and the idle speed will be too high.

Bob

 

[22lbChevelle]

Yea the tps is always between .38 and .44, and the throttle is completely closed. Checked today and the iac is at 00 at idle, but goes up when driving. I plugged in my handy pvc cap with a bike valve stem in it to the turbo inlet and found a big leak at a vacuum T. Fixed that, and a small leak at a intercooler coupler but they didnt help the idle. I double checked the fuel pressure was at the recommended 45psi line off.. 'Tis a weird one..