dieseling engine

[roechambeau]

i got a problem with engine dieseling on my sbc. i adjusted the timing down to about 4 degrees give or take and adjusted the idle down to about 650 rpm. it stopped but it don't seem to have the balls it had and low idle makes cold starts even harder. so i bumped the idle up to about 750 or so and it will diesel every once in a while. what other things should i look at? any ides????

 

[pauly383]

Let it run for 30 seconds or more after you stop moving . That sometimes helps if the carb is too rich and loaded up from driving .

But if the timing is right , drop that idle speed down , if it has no balls , maybe you need to look at the carb , and adjust it , if its stumbling off idle .

You need to say tell us what carb you have .

 

[roechambeau]

yeah it seems to stumble a little but i figured that was just from not being at full operating temp. the carb is a two year old holley 600. i amm not very experienced with adjusting carbs other than idle. but i have a couple of pubs on holleys and am always willing to learn something new. will down-sizing the jets help to solve this? if so will i have to change out the power valve?

 

[69TowRig]

Got the right heat range plugs/clean plugs in it? Shouldn't be much of a problem but it never hurts to check.

 

[roechambeau]

well, letting it idle for 30 seconds or so has helped. as far as the plugs go...i am not sure what is correct. i am running bosch platinums that are for the heads i have. the motor is a 350 with double hump 327 heads. any one have any input as far as plug suggestions????

 

[RustyParts]

Some Chevy engines came equipped with an electric solenoid that as long as the ignition was on it would energize and maintain engine idle, but when the ignition was turned off it would de-energize and let the throttle plate go completely closed to prevent engine run on or dieseling.