I have a 1973 Ford LTD with a 400M 6.6 Ltr engine in it. I have been hit by the gremlins as of late. It wants to continue to run after I complete a trip and turn it off. I can't seem to figure out why. I believe that the Alternator is continuing to charge the system for some reason. Has anyone seen this problem before? Any info that you can provide would be greatly appreciated.

 

Sounds like the throttle is not closing all the way.

Either the fast idle cam is holding it up, the idle screw is set to far or the plates are sticking in the bore.

Ron

 

This is known as 'dieseling'. Diesel engines run off compression heat - not spark. You are running hot. Could be low on antifreeze (bad hose?), could be the carburetor is running too lean (too much air - not enough gas), could be ethanol deposits, could be stuck thermostat not allowing coolant to circulate. Could be your spark plugs are old/improperly gapped(too close). Could be low on transmission fluid and transferring heat to the engine from transmission overheat. GO for the easiest solutions I mentioned first.