New engine dieseling need some advice

[39 Chevy]

I need some help on stoping my engine from dieseling. I've got idle right around 500 rpm's timing is 32 at 3000 rpm's. After my engine get's warm it's still want's to hit a fwe licks when i shut it off.

[rspears]

How hot are you running it, and what's your compression? If it's a new engine you shouldn't have deposit hot spots, so about the only thing I can think of is maybe try a step colder plug.

[39 Chevy]

Driving temp runs 190-195 if I set still for a while around 210

[Bob Parmenter]

You didn't say if injected or carbed. If carbed, check linkage (including kickdown if auto trans) for any bind, as well as weak/misaligned return spring. You might have the throttle plate hanging just slightly open

[Itoldyouso]

There is also one strange, remote possibility, but worth mentioning. Do you have an electric fan? If so, they will generate voltage until they stop spinning. My 27's electric fuel pump and headlights will stay on after I turn off the key for a few seconds and I found out if I shut the electric fan off first those die immediately. A fan motor can become a very efficient generator.

If yours is wired up so that juice can backflow to the coil from the fan, that might be your cause. If you have an electric fan, controlled by an on off switch, do what I did and shut the fan off first and see what happens.

Don

[HOSS429]

nothing i did would stop my V6 chevy pinto from dieseling so i put on this idle solenoid i found on an old ford .. you set the idle where you need it and when you cut the switch off it drops the linkage closed ..

[39 Chevy]

Compression is 10.1 & carbed I'll give the linkage and electric fan a look