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Q: Revs up and out of control

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When I drove on the freeway yesterday my car began to rev out of control. It started to smoke white smoke, so I pulled over and put it into first gear to make it stall. Then I restarted the car, but it started to rev up out of control again. This was very scary, and I need to know how this can be fixed. Why was my car doing this? What’s wrong?

A: Hello. The throttle cable could be sticking...

Hello. The throttle cable could be sticking causing the RPMs to increase excessively if the throttle cable is holding the throttle open when it shouldn’t be. There also could be a bad throttle position sensor or idle control unit. These sensors control RPMs and engine idle. If they malfunction, this problem that you describe is possible. Have a certified technician, like one from YourMechanic, come and inspect your fuel delivery system and throttle body in order to diagnose the revving and smoke problems.

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