Hey everyone, I just got done installing my rebuilt Lt-1 into my car and ever since it warmed up the first time, it has had a high idle (sits right at 2k rpms). I've went over everything I can think of at the moment, only thing I haven't checked was a leaky intake manifold but I just put that pos thing on there, no way it's leaking already. Checked for vacume leaks and found none. Checked for a sticky TB or leaking gasket between it and manifold (replaced), found nothing wrong there. The engine has brand new sensors all over almost. Custom programming from MadZ28 (idle supposed to be at 900). Anything else I should check or look at that would be causing this high idle before I go ahead and redo the intake manifold?

Btw, here's all the info on all the new parts.

New coolant temp sensors (driverside head and waterpump)
New knock module and sensor (lt-4)
Custom Programming
Brand-New 1le Intake elbow (has a new sensor in the elbow, forget what that one is called, ait maybe?)
Egr and Air Deleted (blockoff plates and gaskets installed, air hose hole plugged in the K/n with supplied gromet)
Valve Cover Breather installed, Plugged TB Opening
New Vacume Harness for the Opti
Also, all the unused plugs on the intake manifold was plugged up

That's all I can think of for now, Any help would be great! Thanks.

Btw, I also have new plugs, wires, and optispark but that shouldn't really be related to my high idle. Thanks

 

Do you have a relatively new IAC (idle air control module)? My 94 z has been idling at about 1500 for 10 minutes or so after it is started, then it usually settles down. I plan on replacing my IAC ASAP. I just flipped through the Haynes to find it again but it's not in the index, so I will say, I think the module is right on the side of the throttle body and that it is responsible for telling the blades how far to be open at idle, thereby determining the RPMs at idle. I also think it would probably cost $30 or so for a new one. A friend of mine who's a mechanic says they replace a lot of IACs.

 

No I don't, I did however take it off the TB and clean it up. Later on tonight, I plan on switching TB's with a friend and seeing if it happens to make a difference. Will post the results later on. Thanks

 

After I cleaned my TB, the rpms would "hang". I dabbed some oil on the butterfly rod where it enters the TB housing and the issue was solved.

 

Alright everyone, just swapped out TB's and Maf sensor from a known working car and my car idles right where it should be when you first start it. After driving it around though, the car doesn't seem to want to find it's idle and dies. But as soon as you start it again, it will idle right where it's supposed to be. Any suggestions? I need to get this figured out today. Thanks