1RedLude

Already posted in Tech and after giving it a couple days figured maybe someone in here might be able to shed some light...

Short background info:
Car was an 97 SS 'Lude. I performed the swap over to a manual. Car ran fine for 3 weeks other than an Evap Canister CEL every once in a while. I was then a dumbass and mis-shifted. I pulled the head, had the exhaust valves replaced and then I re-installed the head. Ever since I put the head back on myself I've noticed what appeared to be power loss at high rpms like 6k and above. It also had the idle surges. The other morning I started my car and now it idles at 3k-3.5k rpms. Its insane.
Here's what I've done in attempts to cure it: Took off and cleaned IACV. Took off air intake and cleaned the throttle body. I've checked every vacuum and electrical connection. There is one that is broken but its the vac. line on the IAB Control Solenoid. I plugged both the line and the nipple at the same time with no change in idle. WTF is going on?? Please god someone help me before my car craters its main bearing on startup.

This has nothing to do with the mis-shift. The car has been running for 3 weeks since I put the head back on. The only problem its had is the idle surges. This happened randomly. Car runs fine one night....get up the next morning and it starts idleing at 2k. Its since been moving up....right now its at 3800 rpms. Also, when I push in the clutch w/o my foot on the gas the revs rise an additional 500 rpms before falling back to the 3500-3800. I'm sure its vacuum related and hoped somebody would know of some integral part of the idle system that could cause such a thing.

Oh and I did a compression check today and came back with 185 across the board.

Alos...before this high revving business, if I had the idle set to the correct spot of about 700 rpms...if I accelerated hard then let off and pushed in the clutch it would die at times. I had to put it up to about 1000 rpms for it to not die off hard acceleration.

ONe more thing....before the high revving the car over-heated a bit a couple days in a row...never into the red...just got a bit under it....could the heat have damaged the Idle Air Control Valve?? I'm lookin for any extra guesses at this point.

prelude_b0y

Over heating that motor, I'd say you probably warped the head but just to be sure before going through all the trouble i'd do a CLT test on it first. If that's not the case i'd check the idle air otherwise the fast thermal valve. On my lude my idle surges from 2-3 and the mechnic said i'd probably bent a valve so i took my head off and checked my valves but that wasn't the problem. It turned out that the plastic screw in the fast thermal valve came unscrewed all the way and was just sliding back and fourth in that chamber, so i screwed it back. I'm almost positive that's the cause in my motor cause i've already replaced my idle air valve and tps and my valves seem to be ok. I dunno if this helps any but just thought i'd say something

del_parker

I've replaced my IACV and fast idle and then the new IACV went bad. so now i have the iacv and the fast idle valve blocked off. idles fine now.