Hello all I recently noticed my 88 gxl idling funny. When i start the car up in the morning the rpms shoot to approx 3 to 3.5k for a few seconds then down to about 1.1k, so far so good. after about 5 minutes of warmup the idle starts to fluctuate in an up and down manner, occasionaly it returns to normal but usually I need to rev the motor in order for it to dissapear. The moment I start to drive the problem dissapears. Is this normal if not, what can i do to diagnose and fix the problem? Thanks in advance-Ren

 

It is not normal and I am sure it is fixable The up-down idle is usually a sign of a bad, or out of alignment TPS so I would first check that. I have a how-to on my site.

 

Do the following:

1) Set your idle engine speed correctly using the method described in FSM
If your idle speed is not set correctly to begin with, idle hunting is very likely to happen

2) adjust your TPS

This is likely to solve your problem.
If your problem is not solved, then come back here

FSM (factory service manual) can be obtained at www.fc3s.org under how-to->manual (only get fuel and emissions section)

Hugues -