Engine run-on?

[firedocs]

Not sure if that's the correct term but what I am talking about is when you shut off the ignition the motor keeps running for what seems like forever. I sometimes have to put it in gear and hold brake/release clutch to kill it. History: 1985 CJ7 Laredo - AMC 258 i6 / 4.2l I6, Weber 32/36 (newly installed), nutter bypass. And I have check the timing numerous times with the same end result of "run-on". Any ideas of why and how to stop? Really embarrassing.
Tim

 

[Old Dog]

Your either have to retard the timing or by a better grade of gas. I say buy better gas.

 

[Cheepjeep85]

im leaning more toward the timing, but agree with old dog could be both. correct term, its called dieseling

 

[firedocs]

Alright I didn't think run-on was it. Anyway I will try a better grade of petro, about the timing-6 degrees, 8 degrees??? What is it, some even say by ear is the best. It is currently at 6 degrees above tdc..Idles at 800 rpms still has a "skip" sound at the rear from the exhaust. What do you think?
Tim

 

[kickitandholdit]

dieseling is always funny to me. some cant get theirs to crank and some cant get theirs to shut off. thats a jeep for ya

 

[Old Dog]

It is currently at 6 degrees above tdc..Idles at 800 rpms still has a "skip" sound at the rear from the exhaust. What do you think?
Tim

6* sounds right, the skip sounds like a miss, new plugs and or wires might help.

 

[jeffgtoman]

You may have your throttle plates open too far at idle. This could happen if other things caused you to screw the idle screw in farther than normal to achieve the proper idle speed. Also check your fast idle cam on the choke. Check the actual idle speed. Lower it if possible. A lot of carbs in the early 80's had an electric solenoid to close your throttle plates when you shut the key off. This was to prevent run-on.

Try backing the idle screw out and raising the idle back up with the mixture screws.
Anything to get the throttle plates closed more will help.

 

[jeffgtoman]

I just noticed you said it idles at 800 rpm. Reducing the idle to 650 rpm will probably fix the run-on problem.

 

[firedocs]

OK cool, do you know which one of the many screws is the idle screw on a Weber 32/36? It looks like it has lots of adjustments.
Thanks
Tim

 

[Cheepjeep85]

it'll be the screw close to the throttle linkage with a spring wrapped around it, back it out to idle it down, tighten it to idle it up.