This isn't caused by the Automatic Idle Speed motor. It has enough control to reach 2000 rpm but won't unless commanded to do so with the DRB3 hand-held computer.
The DRB3 scanner can also be used to read the number of "steps" the Engine Computer has commanded the motor to open the air passage around the throttle blade. The range is from 0 to 256 steps. Typical is 32 at idle. If you find it is near 0 steps, the computer is trying to reduce engine speed.
Suspect a vacuum leak at the intake manifold gaskets or a deteriorated rubber vacuum hose. While the engine is still cold, use a squirt bottle to spray water around the hoses and gaskets. The idle speed will go down and the water will get sucked in when you spray the leak.
caradiodoc
Feb 7, 2010 at 12:48 AM
