1998 Explorer stalls

#1

Our 1998 XLT V8 Explorer stalls when cold after starting. It will run only if one holds down the gas pedal. (This makes backing out of the narrow garage and driveway somewhat risky.) After a few minutes of running, the problem disappears until it is again necessary to start the engine when it is cold. On one mechanic’s advice, we replaced the spark plugs. No change. He had hooked some sort of diagnostic machine to the car’'s “computer” and found no problem indicated. The engine light does not come on when it is running.

#2

Try removing and thoroughly cleaning the throttle body and IAC circuit. I’ll bet the IAC circuit is fairly clogged.

#3

There are two screws holding the Idle Air Control Valve (IACV) to the throttle body. You can remove the IACV, and spray throttle body cleaner into the two holes in the throttle body and look into the two holes in the IACV for carbon / grime deposit. Remove with the cleaner and brushes. This action can allow more air during idle, giving a smoother idle. Click: http://www.autozone.com/shopping/repairGuide.htm?pageId=0900c1528018ee43

#4

If cleaning the IAC valve doesn’t help, consider replacing the coolant temperature sensor. If the sensor is sending a false signal to the computer, it won’t adjust the mixture and the idle speed correctly for cold running.

There may be two coolant temp sensors, one for the computer and one for the dashboard gauge. Replace the one that feeds the computer.