engine run on

[mark 66]

my small block 327 has an annoying habit of "running on" after I shut it down. Should I try colder plugs? Where do I start trying to eliminate this problem? Any suggestions would be appreciated. Thanks.:confused

 

[richscorvettes]

There are a few areas that could cause your problem and that you might want to check such as: Curb idle set too high, ignition too far advanced, higher than normal engine temp. and too low octane fuel to name a few. On something like this it's usually best to start with the basics and make sure the engine is tuned to specs. and that all the components are working correctly, especially the carb and ignition. Your engine should run fine on the recommended plugs so I wouldn't suggest changing them unless they are not the ones for your car.

I'm sure others here will offer their thoughts. As an interim measure try using the resistance from the clutch (keep your other foot on the brake) while the car is in gear when you are shutting down. While not a long term solution it will avoid the dieseling until you solve the problem. Good luck with finding the source.

Rich Lagasse

 

[magicv8]

Rich is right. IMO the most common cause is raising the idle to where the primary venturi "butterfly" is open - at which point the engine is trying to idle on the main primary jets instead of the idle jets.

Got A-C?? To get my 66 to idle higher for A-C - but not run on when the A-C is shut off (and the rpm level rises) - I installed a solenoid that holds the idle (up) at the same level when the A-C is on, and lets go when it is turned off.

 

[IH2LOSE]

once your past a good tune to specs.I would knock the timing back a tad,runs better on the gas of today and no knocks.(does your car ping/knock under hard acellaration?) The performance is off a bit but makes for a nicer ride