I have been getting more and more Run On when I turn the key off lately. Maybe it because its cooling off down here and I am not running the A/C and the A/C is not loading the engine and therefor more Run On.
What are the causes of Run On?

_________________
67Cuda,FAST EZEFI,340cu,CR=10.25,RollerCam&Rocker (XR268HR,#20-810-9)(#1622-16)(EddyRPM#60779,#7576), (MSD6AL,#6425) A904, GearVendorsOD, 8 1/4,3.55:1, ClassicAir

Normally it occurs when the idle is set too high. Try turning the defroster on to kick the AC pump in, then shut off the ignition. If you have vacuum leaks it can cause it to diesel on you also.

CJ

_________________
Part of Tyrde-Browne Racing

and put it in park after if stops spinning. Mine does that too when it gets a little hot.

_________________

madam im adam

Other than turning the idle down, some of the suggestions are helpful but not fixes. Do you know of any fixes?

_________________
67Cuda,FAST EZEFI,340cu,CR=10.25,RollerCam&Rocker (XR268HR,#20-810-9)(#1622-16)(EddyRPM#60779,#7576), (MSD6AL,#6425) A904, GearVendorsOD, 8 1/4,3.55:1, ClassicAir

Run seafoam thru to get carbon out. My caravan had this and cleaned up carbon when I had head off and used correct head for the period (carbed 2.2). No more run-ons/dieseling.

Also too high compression ratio for "turbo" or supercharging also can overheat the head as well causing the run on. Even too hot plugs.

Cheers, Wizard

Add a idle speed "kicker" solenoid. Adjust the carb idle screw to the point where the engine will not keep running. Then adjust the idle kicker to your desired rpm. The kicker gets wired into the ign circuit. When ign is on the kicker is engaged and gives the desired idle rpm. When the ign is turned off, the kicker disengages, the throttle closes, and the engine shuts down without run on.
Another way is to install a time delay relay in the A/C clutch circuit, to turn on the compressor, for about 2 sec, when the ign is turned off.

_________________
Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225

Remind us - are you using the extended tip plugs? If so, get rid of those.

Hot spots in the combustion chamber are dieseling the fuel after you shut down, or less likely is that the alternator is charging just enough to keep the ign system going.

Lou

_________________
Home of Slant6-powered fun machines since 1988

I do have throttle kicker and it was adjusted correctly per the FSM yet I still had got short run-on then die. Purrrrr(shut off) CHUG-Chug-chug-dies.
Now after the head replacement & decarboned the piston tops (they were flat-tops with valve reliefs), shut it off, engine just dies right there.

Cheers, Wizard

Autolite 64
No kicker

_________________
67Cuda,FAST EZEFI,340cu,CR=10.25,RollerCam&Rocker (XR268HR,#20-810-9)(#1622-16)(EddyRPM#60779,#7576), (MSD6AL,#6425) A904, GearVendorsOD, 8 1/4,3.55:1, ClassicAir

I had a '75 /6 with run-on; everything seemed at spec and I found that many other /6's of the same vintage had similar problems. I wired up a solenoid valve box to temporarially isolate the vacuum amplifier and apply full manifold vacuum to the EGR valve immediately before shut down; with the EGR wide open, the engine could barely idle, let alone run on.

If you've got an EGR valve, it's an easy thing to try. Just be sure to turn the solenoid on before you shut off, as there won't be enough vacuum while running-on to run the EGR.