Cadillac Allante Forum Discussion, Anyone have a Accelerator problem? in Past Cadillac Vehicle Discussion; My 1988 Allante has a accelerator problem, when you go about 35 miles an hour you cannot stop the car ...
Automobile(s): 1988 Allante' (sold), 1984 Eldorado, 84 Sedan DeVille
Re: Anyone have a Accelerator problem?
First thing to do is remove the rubber throttle body duct from the throttle body and clean the primary throttle bore ( the smaller diameter one) with Brakleen and an old toothbrush. Don't clean the larger bore, the Brakleen can damage the TPS!!! Then disconnect the battery for a minute or so. Reconnect the battery, start the car with the climate controls off. Let it idle in gear for 5 minutes so the computer can relearn curb idle. It will run very rough initially for a few seconds until the brakleen goes away. Then, without shutting off the engine, engage AUTO and 75 degrees on the climate control and again let it idle for 5 minutes in gear. Shut the car off, restart and go drive it. If it still idles too high, you will need the factory service manual to properly retract the idle control motor thru on board diagnostics to adjust the air gap between it and the throttle stop. Normally it should idle in gear at about 650 at normal temperature climate system on or off. I presume the engine temperature is getting to midway on the gauge quickly? Running too cool will keep the idle too high. Should be a 195 F thermostat.
The ISC plunger can be retracted by starting the engine, and placing a flat head screwdriver between they get and throttle plate. Then disconnect the ISC motor (while fully retracted), and adjust the gap to .030 using a feeler gauge.