Engine revving up without input

[SakoTGrimes]

A while back when it was freezing I pumped the gas pedal to the floor a few times before starting and when the engine started it revved up to 2K for a few minutes, just like my Loyale did to warm itself up. That part was OK, but weeks later when I pushed the clutch in it revved up to 4K and was still climbing (no gas pedal) so I put it in 4th to bog stop it. I made sure the throttle wasn't sticking, there was no input, just did it by itself. ???

[555Ron]

Is this carbed? My 86 has a manual choke on it. If you press the accelerator before starting it will rev high when you start it, to disable it after you have started it, just tap the accelerator again.

 

Can't explain the 4k rpm though unless this was after starting?

[SakoTGrimes]

Yes, carbed 83 GL. I was driving and I noticed that the car was keeping speed (25-30 or so) without the gas pedal and that's when I clutched and the engine revved up.

[idosubaru]

check the throttle cables, they can be sticking somewhere along the line. check at the pedal to see if it is physically returning to "idle", maybe it is sticking down. also check in the engine bay that the cables arent' catching or sticking on anything. follow from fire wall to carb.

 

there's probably a return spring on the throttle (not familiar with carbs, never touched one), if the return spring is shot, there's nothing to bring the throttle back down so to speak. i don't know carbs so i think they have something different than a throttle plate, but the principle should be the same with a return spring somewhere.

[Frank B]

Also, clean all the linkages on the carb with a good carb cleaner, and lubricate the throttle cable. With the engine cold, remove the air cleaner to expose the carb. Push the pedal down all the way to engage the fast idle and choke, you should see the choke plate close. Now start the engine and let it warm up while you watch the choke plate. It should gradually, slowly, open up. Once it does, blip the throttle to disengage the fast idle. The engine should be warmed up at this point and idleing fine. But if the choke, or fast idle linkage is sticking, it will rev like you mentioned.

 

Also look for vacuum leaks.