440 keeps running even after its turned off?

[Mike Pittinaro <mechimike@xxxxxxxxx>]

> when i turn my 440 off, especially after a 15 mile
> plus trip, it keeps 
> running after its turned off, i cant remember what

This phenomenon is known as dieseling, named after
diesel engines which tend to do the same thing. 
Basically, when you turn the engine off, you are
killing the electrical system, but the fuel system (at
least on these older cars) will keep going as long as
the engine is spinning.  And, if there is something to
keep igniting the gasoline other than the spark plug,
the engine can keep turning for awhile.

Things that can keep igniting the gasoline include a
piece of head geasket sticking into the chamber,
carbon deposits, or a generally hot running engine in
which "hot spots" in the combustion chamber keep
igniting the fuel.

Try an "Italian Tune-up" first...take the car out (a
tach helps with this) and run it up to about 80 or 90
mph in second gear.  do this a few times, you should
see large black clouds of "crud" come out the
tailpipe...of course, at 80 or 90 mph, you ought to be
looking ahead, watching for police!

Try some carb cleaner next, and make sure the carb is
in proper tune, ie not too rich nor lean.  Also make
sure the timing is set properly.  If the plugs are all
carboned up or otherwise fouled, replace them with a
new set of autolite 85's.  

I've heard drizzling water into the carburetor at idle
will help break up carbon deposits, too, but I've no
experience with this.  Comments from the list?


=====
--Mike Pittinaro

Piles of pitted chrome
Hubcaps along the floorboard
My junkyard-bedroom

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