Thanks for the tips and for the "LC Filter" identification. I'll try this and see if it improves things.

Alex.

Sounds like you may have an ISC (Idle Speed control) problem.
When these units fail they can contribute to a ECU failure. The surging idle rpms suggests there is a problem there. If you send me (at [email]ccnvweb@aol.com)[/email] an email address, I send you a copy the sections of the factory manual to do some simple checks on the ISC.

Cheers!

I think you've found it. That green/blue stripe wire goes straight to the idle speed control motor (ISC), to one of the acutating coil, and is probably causing your idle problems. You need to service the connector. Test the wire for continuity from the ISC to the pin of the connector, and be sure the pin is not pushing back out of the connector when it's plugged in.

So an 1200 mile drive seemed to partially address the problem. At least the surging/revving problem stopped. But was replaced by a low idle. It idles just under 500rpms now. I also took a closer look at the connections to my ECU, and found two connectors that were a little loose when I tested with a pin of a similar size to the ECU pins. I popped the wires out of the connector block, as advised in an earlier post, tightened them up, and put them back in.

I also discovered that one of the "splints" that slipped between the wire pairs in the connector block was inserted in the wrong place (between two empty connections in the block). I moved it back between the correct wire pair, and things seem a little better.

I'm still a little worried about the low idle. I'll be checking the voltage and connections to the idle speed control module next.