[Schurkey]

There's thirty potential causes of dieseling; and I suppose like most tragedies, it takes multiple causes to create a problem--on the edge of too much engine heat, too-lean fuel mix, too-little octane rating, too-hot spark plug heat range, too much carbon in the chambers...on and on.

My experience is that the number one cause of shut-off dieseling is that the idle speed is adjusted too damn high. The idle may be adjusted too high, to "compensate" for crappy air/fuel ratio at idle, not enough spark advance, and lots of reversion from a "lumpy" cam that maybe COULD be tuned-out if the rest of the adjustments were closer to what the engine needed, but then the folks at the Dairy Queen wouldn't be so "impressed".

When the idle speed is turned down to "reasonable", the dieseling is usually over.