What is the Throttle Return Spring all about?
On vehicles that do not have electronic throttle control, or drive-by-wire, there is a throttle cable that runs from the back of the accelerator pedal to the throttle body or carburetor. When the pedal is pressed, the cable pulls the butterfly valve on the carb or throttle body, and allows more air to enter the engine. When the pedal is released, the butterfly valve inside the carb or throttle body should spring closed to its resting position. The throttle return spring is the part that returns the valve to a closed position. There are two types of throttle return springs: one is attached directly to the carburetor or throttle body, while the other is part of the throttle cable. If the throttle return spring is broken, missing, or damaged, the throttle cable will not easily return the valve back to its resting position.
Keep in mind:
- A weak or broken throttle return spring can cause your engine to race.
- If your vehicle is equipped with drive-by-wire, it does not have a throttle return spring.
How it's done:
- The vehicle battery is disconnected
- The air cleaner assembly and defective throttle cable is removed
- The new throttle cable is installed and the throttle is exercised for proper operation
- The air cleaner is reinstalled and the battery is reconnected
- The repair is verified and the vehicle is road tested for proper throttle operation
The throttle spring will last the lifetime on most vehicles. It is not a component that requires regular servicing or maintenance. If the throttle return spring breaks or you experience a related symptom, have one of our expert mechanics diagnose your throttle system.
What common symptoms indicate you may need to replace the Throttle Return Spring?
- No resistance in the accelerator pedal when pressed
- Accelerator pedal doesn’t return back to the top when released
- Engine RPMs will not come down the accelerator released
How important is this service?
Because a broken throttle return spring can cause your engine to race, not addressing the issue can put you in a dangerous position. Have a broken or damaged throttle return spring replaced as soon as it is diagnosed.