Engine revving uncontrollably


I have a 1999 Hyundai Elantra with a 5-speed manual transmission. I had a full fuel injection flush/cleaning and fuel filter replacement done yesterday and the car ran great on the drive home. However, when I took it out to the grocery store later in the day the engine began revving uncontrollably the moment I applied pressure to the accelerator. The engine light came on and I had to cut the engine to get the revving/rpm to stop increasing. It seems as if the engine is just being flooded with gas, as if I was pressing the accelerator to the floor.

Does anyone know what might be causing this problem? Thanks.


It sounds like you have a sticking throttle plate, a sticking Idle Air Control valve, or a massive vacuum leak. Too much air is getting into the intake manifold and you are not commanding that. The fuel system is adding the correct amount of fuel for the air coming in. If the injectors were just adding too much fuel, the engine would be stalling because of an overrich condition. Fuel and air have to be mixed in correct proportions to furn. Have the mechanic look for the cause of the excess air.

Hope that helps


There is a sensor on your throttle called the Throttle position Sensor that tells the computer when and how hard you step on the gas. It sounds like that’s malfunctioning.