gcgarner

Tried the IAC reset procedure today after removing and cleaning the IAC (it was filthy). Well, after I unplugged the IAC, pulled the paper clip jumper, and turned the key, the car would fire but not idle. It would (sort of) run if I gave it gas, but it wouldn't idle. Just died. I did this with a cold motor if that might be the issue.

Also, the instructions are a little vague in the area of the idle set screw. Is the torx screw hidden under a plate that looks like a tiny freeze plug on the BACK driver's side of the throttle body? I tried to hit it with my punch, but after denting it real good and it not moving, I gave up for fear of damaging something.

Thanks for any input.

irocz28boy

iTrader: (2)

Yes, the torx screw is hidden behind that plate. And when you get to it, turn it up as high as you need it to keep the car running with the IAC unplugged. Then you can do the IAC and TPS adjustment. You can do it more than once to keep bringing your idle down lower each time.

rgarcia63

Note: sections in italics are mine.
Proper TPI Minimum AIr Rate Procedure.

1. Ground diagnostic terminal, turn ignition on, but do not start engine.
2. Wait 45 seconds for IAC to fully seat; completely closes the idle air passage to insure all the air enters through the Throttle Body opening.
3. With ignition still on disconnect IAC connector.
4. Disconnect the distributor set timing connector.Very important step, Idle will not be stable if ECM is trying to control the timing. Just don't forget to reconnect when done.
5. Start engine and allow engine to go into "Closed Loop". By the first time the fan turns on the engine should already be in closed loop.
6. Remove ground from diagnostic terminal.
7. Adjust idle speed to specifications using throttle stop screw.
8. Turn ignition off and reconnect IAC connector.
9. Adjust TPS voltage if necessary: With ignition "ON" use a scan tool or 3 jumper wires to adjust TPS sensor to correct voltage specification. Tighten screws, then recheck reading to insure adjustment has not changed.
   Start engine and check for proper idle operation.

If you do not have a stable idle by step #7 this procedure may not solve your problem.
The TPS voltage must be adjusted to match the new throttle position.
Stock RPM gauges can be off up +/- 100rpm[/I] a scan tool, or a precision /performance tachometer would be more accurate.