Guys,
I've looked at the threads on here but don't see any that really are the same as my problem. My 402 just started dieseling when I changed a minor set-up. I swapped my plug wires for new ones and corrected idle speed. When I changed wires idle was off - idled up. Adjusted to correct and now it's dieseling on shut down. Runs way better on the road - actually amazing that wires could have had that much impact...? 2 thoughts come to mind - check timing or adjust fuel rich mixture. Any one seen this before and can save me a couple of hours? Thanks!!!! graemlins/clonk.gif

Dieseling is usually caused by too much throttle plate opening at idle. Check for vaccum leaks, retarded timing, or anything else that would cause you to need more turns of the throttle stop screw to maintain idle speed.