Throttle Cable

What is the throttle cable and where is it located? 

On many older automobiles, the throttle cable, sometimes called the accelerator cable, communicates your inputs at the gas pedal to the throttle.  On those cars, when you mash the loud pedal, the accelerator pedal lever pulls the throttle cable, which ultimately pulls the throttle lever to open the throttle and let more air into the engine.  Then the carburetor or the fuel injection system mixes more fuel with the air and the car speeds up.  In many modern cars, this system has been replaced by an electronic system using sensors and actuators. 

The throttle cable is attached to the accelerator pedal level with a clip or sometimes a bolt.  It passes through the firewall into the engine bay, to the throttle, usually found by the intake manifold.  It attaches to the throttle lever with another clip or bolt.  The throttle cable is housed inside a guide tube. 

How do I know if my ­­­­ throttle cable needs to be replaced?       

A throttle cable is made of braided steel with a rubber coating.  They’re pretty sturdy and can last a long time, but they can wear out and get loose or frayed with time and hard use.  Sometimes the ends of a throttle cable may snag on something in the engine bay and wear out in one particular place. 

If your throttle cable is wearing out, you might notice that your engine doesn’t feel as responsive as it used to.   It may not accelerate as quickly as it used to when you step on the gas.  You might also notice that the engine seems to run unevenly, revving higher or lower sometimes, even though you’re holding the pedal in the same spot.  One strange side effect of a worn throttle cable is that your car might not be able to hold an even speed in cruise control.  Basically, the loose throttle cable is “disagreeing” with inputs from the cruise control. 

In certain dire cases, the cable may snap entirely.  In that case, you won’t be able to open the throttle at all, and the car won’t start. 

If you think you have a throttle cable problem, you can visually inspect the cable.  Look for cracks or fraying in the cable coating.  Check the cable for any play in the cable by hand. 

Can I replace the throttle cable myself?  

Replacing the throttle cable should be fairly easy.  In some cases, you might need to remove other parts to get to the cable.  Depending on your car, removing a wheel to gain access through the wheel well might help.  You’ll have to disconnect the throttle cable from the accelerator pedal, as well as from the throttle.  Then pull the cable out through the engine bay.  If the cable is snapped, you might want to pull the accelerator pedal side out from inside the cabin. 

To install the new cable, start from inside the cabin.  Pass it through the firewall and on through the guide tube until you can pull it out the end.  Then connect the ends to the throttle and the accelerator pedal.  Once the cable is attached, you’ll have to adjust it to the proper tension.  First make sure the throttle is closed.  There are two nuts at the throttle end of the cable: a locking nut and an adjusting nut.  Loosen the locking nut.  Then tighten the adjusting nut until you can only move the cable a millimeter or two by hand.  Then tighten the lock cable.  You might want to test the throttle with your car in neutral before you road test it.