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[mitch1204]

Check your IAC resistance. Hook a multimeter to the two pins and it should be between 6-14 ohms. Are the coolant passages clear?
Then check the BPA (larger pipes) on the IAC. You should be able to blow through freely at room temp. Then heat it up with a blow dryer or heat gun and the valve should move outwards restricting airflow. Coolant is necessary to heat up the IAC. The BPA supplies more air to a cold engine and slowly reduces as it warms up.

Don't pass up the TPS. They can do some weird things. It's basically a variable resistor but it can develop dead spots as one goes bad which confuses the ECM. The ECM will try to correct the situation which could be a pulsing idle.
The easiest way to check one is with an analog multimeter with a sweep needle. You can't use a DVOM as it doesn't see the dead spots. With the meter on ohms slowly move the TPS back and forth. The needle sweep should be smooth and steady. Any dead spots you will see the needle jump.
Last, check the MAF and make sure it's operating correctly. It's return voltage helps the computer determine the injector pulse.

I haven't gotten far on the engine diagnostics on this particular car yet but there might be a trouble code stored leading you in the right direction.

Remember this car is prone to moisture getting in the connectors and grounds under the hood becoming corroded. Make sure all that is clean and seal with dielectric grease.

[greywolf27030]

In my case, I now have the coolant passage out of the block and though the IAC cleared, but the throttle body is stopped up.  I'm going to try to get the flow through the throttle body again, but if not, I may bypass it and see what happens.  After all, it isn't getting any flow now and it runs fine.  I an expecting the weird idle to improve when flow is restored to the IAC.

Jack Byrd