Big Cadillac Keeps Running After Shutdown!

[another Todd]

The reason they diesel with the timing too far advanced is that that causes the idle to be too high. When you turn the key of, the timing has nothing to do with anything because it aint sparking, the ignition is completely shut down. Fuel is being ignighted by a hot spot such as carbon build up or a hot spark plug. And the high idle allows the running to perpetuate, yes sometimes even running backwards.

 

[addyguy]

Two words: WATER DECARB

Seriously, go old skool - get the engine good and warm, remove the air cleaner, and dribble bottled water down the carb while reving it gently. It'll work wonders, and it won't cost much. I did it to my 2002 Cavalier with a spray bottle down the intake, and the car ran noticible better after. An old, carboned-up big block will show even better results!