BACKFIRE through the exhaust.......
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Joined: Oct 2001
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From: Culpeper, Virginia
BACKFIRE through the exhaust.......
I have been posting in the 385 series forum, want to post my woes here for more ideas too add.
First let me say, this motor supposedly rebuilt three years ago, I put on the new timing chain in May, it ran good until recently.
New dissy, I think I'm O.K. there as far as position.
I'm trying to get my truck going, the current problem is I just resealed the intake, seems like I still have a leak somewhere. I was doing the old hose to the ear test, truck was idling (roughly), and she cut off. I went around, cranked her, after a couple revoultions she caught, ran for a second, and then let out a monster backfire through the exhaust. It has never done that before. I've been having a heck of a time trying to get it sealed up. She has a new carb on her, never even driven with it, all vacumm hoses are pulled and blocked right now, all ports on carb are blocked. It was right out of the box, figure it may need adjustment but not much. Wondering what may cause a backfire, and possible consequences. I have help coming Wednesday, but would like to have as much info as possible,too advise him/save us some time, please advise. Many Thanks, Blair
First let me say, this motor supposedly rebuilt three years ago, I put on the new timing chain in May, it ran good until recently.
New dissy, I think I'm O.K. there as far as position.
I'm trying to get my truck going, the current problem is I just resealed the intake, seems like I still have a leak somewhere. I was doing the old hose to the ear test, truck was idling (roughly), and she cut off. I went around, cranked her, after a couple revoultions she caught, ran for a second, and then let out a monster backfire through the exhaust. It has never done that before. I've been having a heck of a time trying to get it sealed up. She has a new carb on her, never even driven with it, all vacumm hoses are pulled and blocked right now, all ports on carb are blocked. It was right out of the box, figure it may need adjustment but not much. Wondering what may cause a backfire, and possible consequences. I have help coming Wednesday, but would like to have as much info as possible,too advise him/save us some time, please advise. Many Thanks, Blair
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Posting Guru
Joined: Oct 2001
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From: Culpeper, Virginia
BACKFIRE through the exhaust.......
I'm at the point where I believe it to be a timing issue. I messed with it all afternoon nad have come to the determination that it is not leaking at all (intake), the noise I hear is that big carb of mine. It is missing pretty hard at idle. I must have the dis in off a tooth or so, maybe last time I rotated it around to TDC, maybe on exhaust stroke instead of combustion. That my thought anyway, maybe my help will prove me right. He's a mech for Ford in N. Va., should be able to straigten me out. 
later, Blair
later, Blair
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Joined: Mar 2002
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From: Wolfforth
BACKFIRE through the exhaust.......
Sounds simular to what one of my ex's did to his 66 pontiac catalina. It had a 400 in it and while he was trying to time it, he wound up blowing the muffler up it was so far off. It was a terribly loud explosion but then, we were in an old Cotton Gin Shop and it echoed around forever! Hope you get it going.
Thanx!
Connie (only Ford luvr in the family!)
'79 f100 "Silver Ghost" (my baby)
'83 f100 "The Ford" (my first)
'85 f150 "Old Blue" (my next project)
Thanx!
Connie (only Ford luvr in the family!)
'79 f100 "Silver Ghost" (my baby)
'83 f100 "The Ford" (my first)
'85 f150 "Old Blue" (my next project)
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Joined: Dec 2001
Posts: 22,436
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From: Louisville,Ky.
BACKFIRE through the exhaust.......
You might want to recheck to make sure that the plug wires are in the right spot. If 2 are switched, it could cause this. Also, try backing out the air/fuel mixture screws about 2 turns until you get it going. Then you can readjust it later. Are you running a Holley? I've been out of town for a bit and I am catching up on the posts.
Jimmy
Jimmy
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Joined: Sep 2001
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BACKFIRE through the exhaust.......
Check for a bad ignition module, distributor pickup, wiring, ignition switch, or a loose ignition wiring connection. A backfire is usually caused by one of two things, intermittant ignition, or an air leak in the exhaust system coupled with a rich mixture.
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