Backfiring while driving, not while sitting still?
#1
Junior Member
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Join Date: Oct 2008
Posts: 23
Backfiring while driving, not while sitting still?
Hope someone here can help me out. I built a 351w, and after finally getting everything put together, it ran great for the break-in. Sitting still, it runs and sounds great. Problem I'm having is when I'm driving it's backfiring out the carb, but only while accelerating. Timing is set right, all vacuum lines are new, new fuel tank, lines, filter, complete new motor, trans, carb, etc. I'm bangin' my head on the wall now trying to figure out why it won't do it while sitting still in my shop, but as soon as I get on the road, Pop.
Anyone have any ideas to help a youngster out?
Thanks!
John T.
Anyone have any ideas to help a youngster out?
Thanks!
John T.
#5
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Join Date: Oct 2008
Posts: 23
Well...not the adjusters, checked them earlier in the evening. Also put a different distributer in it just to make sure it wasn't the pick-up coil. Rechecked the firing order, and all the plugs/wires. No broken parts under the valve covers - everything looks great and new.
Hmmm...bangin my head against the wall one more time. It did start doing it in my shop while in park, but only while revving the motor.
Any other ideas would be greatly appreciated.
Thanks again!
John T.
Hmmm...bangin my head against the wall one more time. It did start doing it in my shop while in park, but only while revving the motor.
Any other ideas would be greatly appreciated.
Thanks again!
John T.
#6
IF IT IS UNDER LOAD THE ONLY THING HAS TO BE SOME SORT OF ELECTRICAL MALFUNCTION :shock: :shock:
I HAVE SEEN A WEAK BATTERY CAUSE THIS SAME THING TO HAPPEN IN A GRANPRIX I WORKED ON :evil: :evil:
JUST A THOUGHT BUT MIGHT BE WORTH CHECKING!!
LIVELY
I HAVE SEEN A WEAK BATTERY CAUSE THIS SAME THING TO HAPPEN IN A GRANPRIX I WORKED ON :evil: :evil:
JUST A THOUGHT BUT MIGHT BE WORTH CHECKING!!
LIVELY
#7
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Join Date: May 2003
Location: Coldwater, MI
Posts: 2,998
Originally Posted by lively
IF IT IS UNDER LOAD THE ONLY THING HAS TO BE SOME SORT OF ELECTRICAL MALFUNCTION :shock: :shock:
I HAVE SEEN A WEAK BATTERY CAUSE THIS SAME THING TO HAPPEN IN A GRANPRIX I WORKED ON :evil: :evil:
JUST A THOUGHT BUT MIGHT BE WORTH CHECKING!!
LIVELY
I HAVE SEEN A WEAK BATTERY CAUSE THIS SAME THING TO HAPPEN IN A GRANPRIX I WORKED ON :evil: :evil:
JUST A THOUGHT BUT MIGHT BE WORTH CHECKING!!
LIVELY
I had one setup that ran fine sitting there but when you got into it, it'd miss ended up being plugs. Assuming you have checked them all, and ohm'd all the plug wires ? What ign setup are you using ?
#8
flat tappet or roller camshaft ?
flat tappets were bad about knocking lobes off camshaft resulting in the backfire your speaking of.
Next i would check Timing chain, also did you degree camshaft ?
i would rule out electrical 1st..but would look here in the end if the rest doesn't clear it up
food for thought.
flat tappets were bad about knocking lobes off camshaft resulting in the backfire your speaking of.
Next i would check Timing chain, also did you degree camshaft ?
i would rule out electrical 1st..but would look here in the end if the rest doesn't clear it up
food for thought.
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Bjuice..
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Bjuice..
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#10
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Join Date: Feb 2004
Location: san antonio, texas
Posts: 1,233
i had that problem one time with the spit fire spark plugs,
went and bought the reliable a/c and that fixed my problem,
sounded like the timing was off, bad spark plug, might
check that, i zapped my hand checking plugs, man what
a charge
went and bought the reliable a/c and that fixed my problem,
sounded like the timing was off, bad spark plug, might
check that, i zapped my hand checking plugs, man what
a charge