!! help lt1 idles too high @ 1500 rpm !!

**onemedina** · 08-07-2006, 01:49 PM

my 94 lt1 idles too high if anyone has any tips please let me know, my camaro has a new distributor, new timing chain, new ignition module, wires, plugs and a set of headers, if you have any ideas please let me know, do apprecitate.

**NinerSevenTango** · 08-07-2006, 07:54 PM

Sounds like a stuck idle air control. You did make sure the throttle is closing, I assume. Also check real careful for any air leaks on the intake system, front to back.

**Chad97z** · 08-07-2006, 09:25 PM

easy.

Check the Throttle body base screw and see if it has been tampered with. If it has, then correct it. The intake valves on the throttle body should be closed or nearly closed at idle. I'm not sure if they are supposed to be totally shut. Follow the haynes book instructions.

If you have SES light coming on make sure you address that first. Could be a bad TPS (throttle position switch). You can verify its output at idle by checking for the specified voltage over the appropriate leads while the car is running. Use a volt meter with sharpened leads and penetrate the insulation near the connector. I think there are 3 wires going to the TPS. One for ground, one for constant high (5v?) and the other is the variable. The varible one to ground is what you jumper. If that is out of specs at idle then correct it on a 3rd gen or replace it on a 4th gen.

If that doesnt fix it, with the engine off, remove the IAC valve and clean it. If the plunger or stopper has carbon build up on it, the stopper wont make a seal and it will allow air to seep in and therefore raise the idle.

If that doesnt fix it, then start checking for a vaccum leak. Can use carb cleaner to spray around the TB and intake manifold while its running. And if the idle surges in a certain spot where you spray, you have a vaccum leak there.