Random Acceleration


TJ Enthusiast
Jun 17, 2020
Ventura County, California
I have an 05 Jeep SE 4.0L 65k miles and at times when I’m reversing the vehicle will randomly accelerate. It did this one before when slowly going forward. I’d slowly hit the gas and then it had a sudden jolt cause the vehicle to accelerate (usually only happed in drive thrus.) That hasn’t happened recently until last week it now happens when I back into my driveway. I’ll press the gas pedal going into my driveway and then I’ll let off the gas but then sometimes the car will act as if I tapped the gas pedal again. Anyone ever experience this before? Should I be concerned?
Gummed up throttle body would be my first guess. Plate might be having trouble returning to closed position. Idle air control valve sticks open possibly.

When's the last time you cleaned it?
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I get that too, just as I'm pulling in my garage. I've cleaned the IAC, still does it.
Guess it just doesn't want the drive to be over yet. :)
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Mine does this too actually. I cleaned my iacv and tb by spraying cleaner in it while it was running let it die a few times. Felt better but still did it anyway. I ordered a new TPS to rule that out. I asked a mechanic he said some Jeeps have something that kicks in to keep the Jeep running in situations where the idle might go to low or something like that. It's in the shop right now so I can't test the TPS but if it still does it after that i'll buy a new iacv sensor... I can afford to throw money at issues like this but others might not so if anyone can get a definite answer it would be a great help.
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You can test the TPS to see if the output voltage is smoothly increasing to ensure the TPS is working properly.

I had this problem coming down the mountain. Rpms went as high as 4500 and back to normal. I think that after I turned off the A/C it stopped happening. Do you guys have A/C?