Gold Lifetime Member
Join Date: Dec 1999
Location: Yorkville, Illinois USA
Dieseling sucks! Remember the basics. For an engine to run, it must have air, fuel, motion, and something to ignite the mixture. With the key off, ignition must come from a hot spot in the cylinder head -- carbon build-up, plugs too hot, etc. fuel and air are easy. If the throttle is opened to normal idle, it will pass air if the engine is turning, and therefore, fuel must be drawn from the carb. The idle solenoid will work, by removing the air and fuel, but it's a band-aid. Clean out the carbon. GM top engine cleaner may work, or just pull the head. Have you changed (or even looked at) the sparkplugs?