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Old 04-25-2013, 09:48 AM   #1
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Exclamation sudden acceleration...Scary

I have a scary problem, 2002 Boxster S E-Gas. The last few weeks the idle/acceleration wants to go on it's own. It happens more on cooler days then warm days. when the engine gets close to 180 degrees all of a sudden if at a red light it wants to jump, RPM's go to 1500-1800. It also does it on the highway when reaching about 65 mph. I have cleaned the throttle body. No CEL or vacuum leaks that I can find.
Need help!!!

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Old 04-25-2013, 10:59 AM   #2
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I think you should get that looked at before it ends in tears.
'99 black 986
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Old 04-25-2013, 01:49 PM   #3
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may be the gas pedal position sensor or...definitely get it looked at sooner than later
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Old 04-25-2013, 02:14 PM   #4
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Maybe a dirty or otherwise gummed up sensor for the pedal? Have you been running the A/C? I know my car tends to have a slight idle jump to compensate for the load when the compressor kicks on/off, but not as high as what you're saying.

Does it only seem to happen when the vehicle reaches close to operating temp and when the vehicle gets up to highway speeds? Does it do it at any other times?

Any other issues you've noticed, particularly of the electrical variety? If so, I'd say maybe grounds and/or ignition switch.

Either way, if you don't find the culprit soon I'd say bite the bullet and get it to a dealer or independent specialist. It'll end up costing you a lot more, and not just financially, if you lose control of the car and damage it or another person's car and/or injure yourself or someone else.

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Old 04-26-2013, 06:00 AM   #5
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It really only happens when close to operating temperature. where is the gas pedal sensor? I might try cleaning that first. Could a dirty od bad MAF cause this problem as well? I change my filter regularly, but I haven't checked the MAF.
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Old 04-26-2013, 07:03 AM   #6
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the computer decides, in part, how much gas to give based on engine temp. try disconnecting your battery to reset trims. if that doesn't fix it, perhaps you have an oil/coolant temp sensor gone bad.
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Old 04-26-2013, 07:13 AM   #7
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Check the integrity of the accelerator pedal hinge.

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