1995 Bonneville SSEi Supercharged, Irratic idle
The car warm or cold will not idle at one speed. When i first start it cold it will idle up to around 1800rpm'* or so and then when it should drop to normal idle speed of about 1000rpm'* it keeps going down and almost stalls and then it will idle up again and down again and never stays at the same rpm'*. Once it is warm I can stop for a light and the idle will drop to about 800rpm'* or so and almost stall. When I stop for a light the idle does not race it just drops. It may not race because I have it in drive.
I have recently replaced MAF, Ignition control module, plugs, wires, 02 sensor, coil packs, IAC valve and about two years ago the EGR valve.
I was having vacuum leak issues with the EGR tube, but I believe they are taken care of.
When the idle drops you can smell it chocking out, runs rich.