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Discussion Starter #1
OK...this is probably a simple-minded question...but what causes the engine to try to run on after you turn off the key? Too much advance?:confused: Its kind-of embarassing and I'd like to get it solved before Good Guys.

Thanks

Dave
 

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hmm

could be a host of items , poor quality gas , carbon buildup thats retaining heat in the chamber sufficient to provide ignition , what carb and what condition is it in ?? , idle set up that may be too lean , restrictive exhaust ,,, just a few places i'd look . Something is causing it to retain enough heat for spontanious combustion without an obvious ignition source. A good flush of the cooling system might help as well or a general check up of the cooling system might be in order. There is a passage near the plug side of the chamber that might have some corrosion built up thats might be acting as a thermal barrier and not allowing heat to escape to the cooling system out of the head.

My dad back in the day would always bring a car just above idle a couple seconds then shut it down to reduce this condition.
 

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As a temp fix shuting the engine off in gear will usually stop the engine with an auto trans. With a manual trans just ease the clutch out as you shut it off with your foot on the brake.
 

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If its auto then shut it off in gear 'till ya figure it out. My truck motor (350 with a 4 speed) is happy as low as 750 rpm and dosen't like to idle any higher than about 900 rpm or it tends to run on. New re-build, heads, carb etc.
 

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On one of my cars that had an MSD on it, I had to install a diode (I believe) on one of the wires on the alternator. This was a long time ago, but I think that there was something about too much power stored up and the car ran on for a little while. Instlaled the diode and problem gone
 

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Discussion Starter #7
Thanks guys...really appreciate your advice. What's puzzling me is that it was not doing this before I yanked the engine to rebuild the rotating assembly.

Carb is a Holley Street Avenger 670. Advance = 13 deg at idle. New plugs in vortec heads (but didn't take the heads off in the rebuild). Cooling system got flushed and refilled during the rebuild.

So a lean mixture could cause it? I need to check that out. I probably have it on the lean side.

Dave
 

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Like T'shirt said , low actane gas , the gas we have now days is crap!!!
Try some higher octane or some octane booster might help.

Roger
 

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Discussion Starter #9
All we have here in sunny CA is the 91 stuff. I think I had better dial back the advance a little more, huh?

Dave
 
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