I have a 1993 Dodge Caravan (I'm also the original owner) that has abad idle problem we can't figure out. BTW - it's a manual 5-speed, 4 cyl. It starts and runs fine EXCEPT that it idles high, but consistent. It will idle so high that it feels like parts will start to fly off. It will be ok for a little bit. Then when I start the car I feel the idle is a little high, and it will stay consistent for that drive. When I start up again, it idles higher. Then each consecutive drive the idle is higher until it's way too much. Then as mysteriously as it appears, it goes away and is good for a day or so. Then the cycle begins again. It doesn't matter if it's hot, cold, short or long trip/drive.

When I brought it to the shop, they found a lot of error codes came up: "extracted multiple 33 = Air Cond relay (I have no AC), 25 = automatic idle speed control circuit, 24 = TPS high, 22 = coolant voltage high. Because they found many codes, and searched and found nothing else, they felt it was an electrical short in the computer and replaced it (ECM).

Well, it wasn't the computer, because the issue is still happening. Could it be mechanical, electrical short or a valve leak? The engine's still strong (for 235,000+ miles)! I'd appreciate any ideas or experiences.

Also, I've been bringing it to the same repair shop since I bought it.

Bill

 

Are you still getting any codes after ECM replacement? I would start back at the codes you got before and check those things.

 

Since it's happening today, we're going through and checking if any codes come up with the new ECM. Definately good idea to go back over the codes from the old ECM and check those things physically. Thanks...will update

Bill