Dieseling

[xlandyx]

Hey guys. 1963 2a with a new turner engine. Valves are set, timing is right on, idle is good, but still getting some Dieseling when shutting down. Suggestions?

[lumpydog]

- Lower the idle to 500-600 RPM. Lower is better but not so much it stalls when stopping.
- Use 90 octane fuel (You may need to adjust timing a little)
- Make sure there are no leaks in the intake or carb.

[lumpydog]

P.S. Others may tell you to get a fuel cutoff solenoid. They are not necessary in my opinion - and - add problems.

Cut off solenoids were added back when emissions laws were enacted and it was necessary to have a high RPM idle to pass emissions. That made the engine prone to dieseling. Solenoid cutoffs are prone to failure and add to the things that need to be checked when the engine won't start.

[o2batsea]

If it's dieseling, then the timing is not right.

[I Leak Oil]

Timing, wrong plugs/gap, hot spot. Newer motor? Probably timing.

[blueseriesii]

Dieseling,

Giving the throttle a jab and holding it open while turning the key off will suck a bunch of cold air through the system thus cooling down the hot parts. This works for me on a number of engines. It doesn't solve the underlying problem but does stop the run-on. (It also suck in some raw unburned fuel too)

Doug