Car Engine Idles Very High

car idles too fastI want to ask you a tech question – my wife today had a very unpleasant experience.

Our car automatic Toyota Corolla was parked near the shop by my wife. When she started the car after wards – it gave very high revs (engine was idling very high) . She did not re-start it and switched to reverse. The car JUMPED backwards and hit another parked car.

We were very lucky that some kids who were standing there a minute ago moved to another place.

Could you say what is the possible reason?

In a half-hour friend of mine got there and started the car – NO PROBLEMS…

Thanks in advance

Sincerely yours

Hi Igor,

That is odd! You might want to look around under the hood at the throttle cable and make sure nothing is in the way that might cause it to stick. I would also look at the floor mat on the driver’s side, to make sure it is not pushed under the gas pedal and might have caused the pedal to stick. I have actually seen this happen twice.

I would also inspect the throttle body, and make sure it is clean and there is nothing inside restricting the large valve that is used to mix fresh air inside the engine. I have seen large amounts of carbon build up inside the throttle body and cause the valve to stick, thus stick the accelerator cable.

Watch my video and take a look inside your throttle body too

I would also make sure there is not a vacuum leak. Open the hood with the engine running and listen for any kind of hissing noises, and look for any rubber vacuum lines and hard plastic hoses that might be cracked or pulled loose.

A vacuum leak can cause weird idle problems, too slow or too high because the engine computer is trying to compensate for the leak and adjusts fuel and air mixtures…and usually does a poor job at doing to.

I have seen, many times actually the oil change mechanic leave the air filter hose or the top of the filter box loose and it will cause a vacuum leak and set a check engine light to come on.

Last thing I would look at is the throttle position sensor. This sensor sends an electronic signal to the engine computer letting it know where the position of the throttle cable is and how much fuel to send to the engine. Usually you don’t see to many problems with this sensor, so please have someone check voltage and resistance to it before just guessing and replacing it.

Please share this with your friends,

Austin C. Davis

Posted in: Running Problems

Got Something to Say?