: 1993 Cadillac sts 4.6 idle fluctuating

10-20-09, 03:17 PM
I start my car in the morning idle goes from 1000 to 2500 RPM S I'd tried puting it in gear cannot drive it tell about 20 minutes and it goes back down to normal I replaced the ISC and it still does the same thing can anybody please help me I would like to thank you now for your help.

10-20-09, 04:56 PM
Look for a vacuum leak. Maybe around the intake manifold cover.

10-21-09, 11:50 PM
Ranger thank you very much for answering my question but I've found what was making my rpm to go up and down it was the gray wire in the plug that plugs into that EGR I've been reading so many of the same symptoms and no one has ever gave this answer. Ranger I believe you are the smartest person on this whole site and most responsible person I wish the rest of the people would follow in your footsteps

10-22-09, 11:56 AM
Thanks, but you give me FAR more credit than I deserve. There are several people here who probably are more knowledgeable than I.

10-26-09, 04:25 PM
got similiar problem. where is the EGR on these northstars? when you said the gray wire in the plug was bad, was it a vacuum gray wire or an electrical gray wire?

10-26-09, 06:11 PM
The EGR is to the right of the TB when looking over the drivers side fender. Big black canister with a plug on top.

10-26-09, 07:33 PM
This os on my 94. Your 95 looks the same but without all the plastic stuff over it.


10-27-09, 01:52 PM
thanks, Ill check it out.