Just put a brand new Sorenson IAC valve in my 88' Camaro. Car is idling at ~2250 rpm now. TPS is .54vdc. Idle adjustment screw is backed all the way off the butterflies. Timing hasn't changed since this morning.

HELP!!!

Thanks guys.

 

i had my 95 camaro do the same thing it ended up being the tps. i dont really know how to check that. but for me that is what i had to do to get it to idle normal.

 

The TPS is adjusted almost all the way forward, I'll forget about the voltage, and just try moving the adjustment the other way, see if that will lower the idle.

 

ADJUSTING MINIMUM AIR:

Procedure I followed:

Jump ports A and B on the ALDL.
Turn on Ignition, Wait 30 seconds.
Unplug IAC.
Start Engine.

This is where I run into the problem. Instead of being able to adjust the RPMs down to 450, The lowest I can get them is 1500. The idle speed screw is still backed all the way out, to where the butterflies won't even come back far enough to meet it.

Is it possible that the IAC isn't working? Maybe it's letting too much air through and keeping the engine at high rpms?

 

I have always had good luck when changing iac valves just by measuring the length from the end of the pintle to the base of the valve, it should be 1,1/8 inch. This works as long as you havent messed with the idle screw.

 

It is possable that that is the problem. NEW stand for never ever worked.

ill check our program here to see what some procedures are for checking both.

 

ok here we go:

this is for adjusting the TPS

1. Unplug electrical connector at TPS and install jumper wires between the three terminals.
2. Connect a digital voltmeter to signal voltage terminal and sensor ground. NOTE - See code 21 wiring diagram for terminal identification.
3. With ignition on engine off, check voltmeter reading. If not to specification drill out spot weld on adjustment screws (if used).
4. Remove screws and apply thread locking compound and reinstall screws.
5. Rotate TPS until desired voltage is obtained, and tighten screws.
6. Ignition off, remove jumpers and reconnect TPS harness. Clear any trouble codes stored.

here are the test procedures for the IAC
(pic below) you should be able to click the picrture. now i have to hold the mouse over the pic in the new window then there will be a box that appears in the corner that will allow you to read it.