How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Tech444 Your Own Question
Tech444, Ase certified Honda certified tech
Category: Honda
Satisfied Customers: 963
Experience:  17 year Honda Master Tech troubleshooting specialist all includes electrical
Type Your Honda Question Here...
Tech444 is online now
A new question is answered every 9 seconds

Why is my car accelerating on its own

This answer was rated:

Within the first half hour of driving (after having been sitting for overnight or for hours), at some point the engine revs and the car goes forward as if I am still giving it gas (though I'm not) and I have to apply the brakes (firmly), pull over, apply the parking brake, turn off the engine. When I turned it back on, the engine was revving at 5000 rpm in Park. Turned it off. This has happened twice before in the last week or so. After this last instance, I punched the accelerator pedal (when the car was not running) a couple of times, thinking it was stuck (but I'm pretty sure it wasn't). Turned car back on and it was idling OK. What's wrong? My dealer's mechanic did not know. Guesses it could be rotary air control valve, but can't be sure. (Not that it's related, but a week earlier I had my transmission replaced -- Honda recall/warranty extension.
Well id bet that the throttle cable is broke or bent when doing the transmission bring it back to who ever did the transmission tell them to check the throttle cable as i seen this exact thing before
Customer: replied 10 years ago.
Reply to Tech444's Post: the dealer just called me. they were the ones who installed the transmission and they say they have inspected the throttle cable and it's ok. they thought the throttle body was blocked but they checked it and it's ok. they think it's that rotary air valve (?) and suggest i leave car overnight so they can take it out on the road when the egine's cold in the morning. is this a fuel injection system kind of problem?

Well the rotary air valve would make the rpms go up and down if this is happening then yes its possible but sounds to me when they put the sling when they did the transmission the broke the throttle body which is where the cable goes im 99 percent sure they need to replace that throttle body as this wasnt happening till after the tranny repair make sure they replace the throttlebody and order it tonight so they have it for tomorrow or they will have your car another night also you are entitled to a rental or loaner car make sure you get one

Well glad to help

Bonuses greatly appreciated

Tech444 and 4 other Honda Specialists are ready to help you