Backfiring while driving, not while sitting still?
11-18-2008, 03:30 PM
#21
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RACING JUNKIE
Join Date: Jun 2003
Location: Hobbs, NM
Posts: 842
John start your engine and let it warm up a second and then take spray bottle with water in it and spray each header tube close to the head, to see if you have a cylinder not firing or weak. The water should sizzle and evaporate immediately.
11-18-2008, 07:24 PM
#23
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RACING JUNKIE
Join Date: Jun 2003
Location: Hobbs, NM
Posts: 842
John do you have another carb to try? It would be nice if we could eliminate the carb as the problem. There is a lot of things in the carb that might cause this--bad power valve, bad base gasket, debris in jet, ect..
11-18-2008, 10:52 PM
#24
Senior Member
MASTER BUILDER
Join Date: Jan 2008
Posts: 146
how would it be a lean issue, when its not getting enough fuel ?
and its coming back through the intake valve! so why is it firing when the valve is open
it still sounds electrical/advance some how?
wrong distributor gear?
and its coming back through the intake valve! so why is it firing when the valve is open
it still sounds electrical/advance some how?
wrong distributor gear?
11-19-2008, 07:12 AM
#25
Junior Member
APPRENTICE
Thread Starter
Join Date: Oct 2008
Posts: 23
I don't have another carb to try, unfortunately (unless I snatch the one off my father's 64 Fairlane, but I like being alive 
) so tore mine apart last night. It's got 63 jets in front, wiht 80's in the back, put in a new power valve (6.5), and everthing in it was still Really clean.
Not sure if I posted it, but I did put a different distributor in it night before last with no luck on that either. Also tried a different ignition box (motorcraft).
My father told me that I may have the wrong size pushrods in it. The cam Grind # 270-2h 204/214@50, 270/280, 448/472 from Crane. It's got stock size pushrods in it now. I called Crane and found out how to measure and get the correct size, just to rule that out too.
) so tore mine apart last night. It's got 63 jets in front, wiht 80's in the back, put in a new power valve (6.5), and everthing in it was still Really clean.Not sure if I posted it, but I did put a different distributor in it night before last with no luck on that either. Also tried a different ignition box (motorcraft).
My father told me that I may have the wrong size pushrods in it. The cam Grind # 270-2h 204/214@50, 270/280, 448/472 from Crane. It's got stock size pushrods in it now. I called Crane and found out how to measure and get the correct size, just to rule that out too.
11-19-2008, 11:39 AM
#30
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RACING JUNKIE
Join Date: Apr 2003
Location: Greenville s.c.
Posts: 3,236
if all else checks out and it seems you have ruled out eletrical and you got to go into the engine..i would start with cam and timing chain....I PERSONALLY think your gonna find your problem somehwhere between either one of these and i'm gonna say wiped out lobe on camshaft...
( Not that you did something wrong but that it just happens )
everything you have stated leads me to this conclusion...i mentioned this earlier in the post with a few reservations but i am almost convinced at this point.
i am sure you will find it either way
( Not that you did something wrong but that it just happens )
everything you have stated leads me to this conclusion...i mentioned this earlier in the post with a few reservations but i am almost convinced at this point.
i am sure you will find it either way
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Bjuice..
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