My 94 Seville has 158k miles. Recently the idle has begun surging. At first it would surge up to 1200 to 1400rpms. This would occur very sporatically (maybe a couple of episodes every couple of months). Recently she's gotten much worse; surging up to 3000rpms and only occassionally dropping down to the normal 700-800.
I've scanned this form and don't see this problem addressed. Any ideas would be greatly appreciated.
Any kind of clicking or ratcheting sound when you start or shutdown? Check out the ISC motor...search for threads on it, as that was a symptom I had just before I replaced mine...there are other things it could be as well, but that's what fixed mine...also check the fpr, by taking off the intake cover and turning the key to ON...DON'T START THE ENGINE WITH THE COVER OFF...it will run away at WOT. watch for a few minutes, and if any fuel drips out of the fpr nipple on top, it needs to be replaced. Much more detail on this as well if you search for it...but give those two a shot! Good luck...there are many on here who know a whole lot more than me, and I'm sure one of 'em will guide you in the right direction.