RPM's won't drop,every time I give it gas it raises more.

[AAA]

I have a '77 CJ5 that started having problems about 2 weeks ago when I was driving down the road, it stalled while driving and would start but die immediately after letting go of the key.I posted the thread about having no power to the ignition coil positive wire and I thank everyone who helped,but as of this morning I'm having yet another problem I need help with.When at idle if I press the gas pedal the rpm's keep raising and not dropping at all.If I put it in gear it will accelerate itself and when I press the clutch in the rpm's raises to around 2500 rpm.I can't really drive it to my mechanic because I'm afraid of the engine blowing at a stop light unless I shut it off as well as it being hard on the synchronizers when shifting.The rpm's just won't drop, it just raises and stays raised with every tap of the throttle pedal.My first thought was a sticky throttle cable but it doesn't appear to be stuck anywhere,of course I'll keep checking it over but is there anything else that could be the cause?

 

[JimsCJ5]

Sounds like a stuck throttle or a bad vacuum leak. Disconnect the throttle cable/linkage and work it by hand to see what it is doing. I assume you have a functioning throttle return spring?

 

[TnCJ]

Have you checked the throttle return spring? My Carter has two.

 

[jp360cj]

As mentioned, disconnect the linkage and see it if goes away. If it does, then you may need to replace the return spring, lube the cable, or both.

 

[mriplaybass]

When the engine is racing, look at the idle stop screw on the carburetor. If the screw is in contact with the stop plate, try backing the screw off, although, if it ran correctly before, and you haven't adjusted it, it should be OK. If it's not in contact, the throttle is staying partially open and you probably have a sticky linkage or throttle cable. Try disconnecting the throttle cable and working the carb linkage. If it sticks, clean and lubricate it. If it returns to where it should be, but the engine still races, start looking for a vacuum leak. Do the same with the cable. Although it's a long shot, look down the carb throat and make sure that the throttle plates haven't broken loose. They are attached by 2 small sort of rivets. If one of them wore loose, the throttle plates can't seat properly.

 

[Kane]

If you have a dual return spring they could be getting caught and tangled up which will hold the throttle open. Also the high idle cam on the carb for the choke could be getting hung up and keeping the throttle open as well.

 

[Scout1067]

I had a similar problem with my 81 CJ7 last year. Turned out to be both a worn throttle return spring and dry linkage. I out a new return spring on and lubed up the throttle linkages. One of the rare simple fixes.

Sent from my ALE-L21 using Tapatalk

 

[Manic Mechanic]

i agree with everything stated above either spring cable or choke could also be a vacuum leak. u can check for that using carb cleaner and spraying around the base of the carb and listen for the idle to jump a few notches