: Anyone have a Accelerator problem?



tjk5405
06-15-13, 09:59 PM
My 1988 Allante has a accelerator problem, when you go about 35 miles an hour you cannot stop the car without putting it in neutral , any info would be appreciated.

D Yaros
06-16-13, 11:17 AM
This sounds more than dangerous to me? Have not heard of/seen this before. Please let us know the cause and solution.

MoistCabbage
06-16-13, 04:23 PM
Cannot stop the car in drive? You could floor it and the brakes would be able to bring the car to a stop. Do you mean that it will maintain 35 without throttle?

tjk5405
06-16-13, 06:50 PM
Cannot stop the car in drive? You could floor it and the brakes would be able to bring the car to a stop. Do you mean that it will maintain 35 without throttle?

Yes it will maintain the speed, I believe it's the idle control motor , but not sure

carnut
06-16-13, 08:21 PM
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.

MoistCabbage
06-17-13, 01:00 AM
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.