Throttle or other?



While sitting at a traffic light my vehicle (a diesle engine) will automatically rev up… This will occaisionally happen when I am driving on a freeway as well (which will cause the car to speed up). What could be the cause?


You MAY have a loose or broken TPS.(Throttle Position Sensor)


That seems unlikely since diesels don’t have throttles.


Something could be blocking the intake, but I doubt it. I noticed that when we blocked the intake (with our hands) of a Cummins 972 V-8 diesel engine that we had in school, the engine would rev up like crazy. After checking the air filter, the next stop may have to be at the shop. We didn’t learn anything about diesels, we just started it once a year.