Engine continues to run after shutting her down?

sounds like dieseling. best bet is to start with some top engine cleaner and run it through the engine to clear out the carbon that may be in the combustion chamber. The carbon stays hot enough after running the engine for a while that it can ignite the fuel still coming into the engine. The top end cleaner (or seafoam) aims to clear out carbon from the engine and should help. but before using be warned it can also clean out things such as intake gaskets and stuff and cause more problems so use it at your own risk but many have used it with much success. An oil change after using it isnt a bad idea either.

Check your timing make sure it's not too far advanced, should be around 12 BTDC. Also what is your idle speed set at? Too high of RPM at idle can cause run on also. Having the carb too rich and too hot of plugs can also mess with this.

Besides what was previously mentioned. Are you running a electric? If so i have seen and had one back feed electrical system and keep car running for a few seconds until fan stops. Try unplugging it from power source and see if problem continues.

All of the above as well as way too high of an idle can let enough fuel/air mix to sneak past and diesel. Around '73 GM added a solenoid to the carb so it would hold it open to run at idle speed yet close totally at shutdown so no dieseling. An MSD box needs a diode in the alternator wire because even 1/10th volt will support spark.

Hi All of the above but if you are like me, i love more timing in a engine and it does the same so i shut my car down in gear.

i had that problem until i added ground straps from motor to body

a vacuum leak will do that too,it happened with my s10,spray your lines and around the carb base,and see if the idle changes

Mine does it when I run 87 octane - 91 or 93 it doesn't