1966 Ford F-250 backfire

1966 FORD F-250
10,000 MILES • 6 CYL • 2WD • MANUAL
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SFATKISSON
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  • 1 POST
Truck starts and runs good; also idles well, but continues to run when ignition is turned off and sometimes backfires loudly, then is difficult to restart. Takes several attempts to restart engine, problem is consistent. Truck always starts good when engine is cool.
Jul 24, 2015 at 1:49 PM
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HMAC300
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  • 48,601 POSTS
check your ignition switch it may be bad causing the running after off and check wires near starter relay youmay have one in the worn position. for back fire check for a cracked dist cap or coil
Jul 24, 2015 at 3:52 PM
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CJ MEDEVAC
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  • 11,004 POSTS
I DON'T KNOW THE TUNE UP SPECS FOR YOUR RIG

IF YOU HAVE IT SORTA TUNED UP PROPERLY IT SHOULD IDLE AT THE CORRECT IDLE SPEED.

MY BEST-US GUESS IS YOUR IDLE SPEED SHOULD PROBABLY BE SOMEWHERE BETWEEN 700 - 800 RPMs

IF WHAT YOU "MEAN" BY IT CONTINUES TO RUN WITH THE KEY OFF, IS IN ALL ACTUALITY SPITTING AND SPUTTERING THEN FINALLY DYING, WITH THE OCCASIONAL BACKFIRE (SOME FOLKS REFER TO THIS AS "DIESELING")

IF YOUR IDLE SPEED IS HIGHER THAN IT SHOULD BE (EXAMPLE, MAYBE 1200 RPM), IT CAN DO EXACTLY WHAT I DESCRIBED IN THE PREVIOUS PARAGRAPH

IF YOU BACK OFF ON THE IDLE SPEED AND IT WON'T RUN (IDLE), YOU NEED TO DO SOME CATCHING UP ON YOUR TUNING AND MAYBE LOOK FOR A POSSIBLE VACUUM LEAK, IF ONE EXISTS

LET US KNOW HOW IT GOES

THE MEDIC
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Jul 24, 2015 at 7:11 PM
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