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Old 01-02-2013, 05:45 PM   #21
1crosscut
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Default Re: backfire

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Originally Posted by jerry of whidbey View Post
poling choke makes no diferance modern distrebutor bran new less than a hundred miles
Did this start before or after the new modern distributer?

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Old 01-02-2013, 05:51 PM   #22
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Default Re: backfire

Did you have this diveablity problem before you changed the above mentioned parts?

I had a freak battery issue back in the 80's that caused the same symptoms, took a while to discover the culprit, replaced the battery and all was good.
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Old 01-02-2013, 06:31 PM   #23
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Default Re: backfire

Hmmm, I had exactly the same symptoms recently. Come to find out I had a cracked ear on the Zenith carburator which would expand when warmed up, allowing a healthy vacuum leak. Something to check anyway.
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Old 01-02-2013, 06:41 PM   #24
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Default Re: backfire

Original armored cable? They get squirrelly. Don't thread the ignition cable too far into distributor, it will cause a intermittent short by pushing the condenser bus bar into the distributor housing. These won't readily show on the amp meter.
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Old 01-02-2013, 07:08 PM   #25
jerry of whidbey
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Default Re: backfire

thanks for all your help going to work on it again tomorrow and study all your help tonight .LOVE FORD BARN. JERRY
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Old 01-03-2013, 05:56 AM   #26
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Default Re: backfire

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Quote:
Originally Posted by Greg Jones View Post
Hmmm, I had exactly the same symptoms recently. Come to find out I had a cracked ear on the Zenith carburetor which would expand when warmed up, allowing a healthy vacuum leak. Something to check anyway.

Yes, Electrical or intermittent Electric/Ignition will Not cause backfires through Carb or exhaust.
-Unspent gas may -occasionally- be ignited in muffler but that's as close as it will get to anything remotely similar to a backfire. Odd backfires in muffler indicate electrical/ignition as the unburnt gas accumulates in the exhaust.

Carburetor and/or Vacuum leaks Will cause carb backfires.

jmho


moe


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Old 01-03-2013, 09:02 AM   #27
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Default Re: backfire

Say what?
Ignition problems WILL cause backfires in the muffler. When my repro ignition switch was making intermittent contact I had several loud explosions out the exhaust. It was louder than shotgun blasts.
Luckily my new Aries stainless muffler held together.
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Old 01-03-2013, 10:14 AM   #28
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Default Re: backfire

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Say what?
Ignition problems WILL cause backfires in the muffler. When my repro ignition switch was making intermittent contact I had several loud explosions out the exhaust. It was louder than shotgun blasts.
Luckily my new Aries stainless muffler held together.

got that right i have one in the bay now with a f** up modern dist plate that was acting up int. it backfired so loud in the shop i had to go change my underwear and the poor lady sitting in the waiting room while her car was being fixed almost had a heart attack
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Old 01-03-2013, 10:35 PM   #29
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Default Re: backfire

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got that right i have one in the bay now with a f** up modern dist plate that was acting up int. it backfired so loud in the shop i had to go change my underwear and the poor lady sitting in the waiting room while her car was being fixed almost had a heart attack
Hahahaha... I wonder who owns that A.
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Old 01-04-2013, 11:04 PM   #30
jerry of whidbey
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Default Re: backfire

well we did a lot of things as all of you suggested one at a time and then test drove it. nothing worked. we replaced distributor carb coil checked for lose wires on popout did not repalce popout checked wires behind dash, poling choke no help, turning the cav no help. Gary Formhals presadent of Whidbey Island A's have worked on it for two days no help but thanks will go at it again tomorrow
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Old 01-05-2013, 01:02 AM   #31
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Default Re: backfire

Back many years ago I had a problem where the car would develop a very rough running condition, and loss of power after being run for about the same amount of time as you suggested in the first post. After going thru a similar list of parts replacements, an older fellow who ran a restoration shop suggested using some Bardahl. Couldn't find any, but did try some STP thru the carb. After three restarts, short drives, and cool-offs, the problem left and never came back. Final diagnosis was multiple stuck valves, once engine reached operating temp. If this is your problem, I would guess the number stuck is likely less than mine !!!
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Old 01-05-2013, 09:46 AM   #32
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Default Re: backfire

Has a compression ck been done?? Timing marks verified??
Paul in CT
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Old 01-05-2013, 10:46 AM   #33
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Default Re: backfire

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Has a compression ck been done?? Timing marks verified??
Paul in CT
Been running for 1000+miles no problem> no compression ck yet. New engine.
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Old 01-05-2013, 12:01 PM   #34
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Default Re: backfire

A vaccum guage connected to the intake while driving might help find the problem. If the needle starts to flicker at the same time the problem begins, then look for sticking valves. A can of Sea-Foam in the gas and another can in the oil might fix it.
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Old 01-05-2013, 06:23 PM   #35
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Default Re: backfire

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A vaccum guage connected to the intake while driving might help find the problem. If the needle starts to flicker at the same time the problem begins, then look for sticking valves. A can of Sea-Foam in the gas and another can in the oil might fix it.
Just got back from another test by-passed the pop out- did it again! Shorted out the plugs while hot and running of course One and four did nothing, 2 and 3 the engine idles down! Sounds like valves sticking??? Injected mmo in the carb while hot waiting for cool down in the Am We will try the stp in the carb trick. after that pull the valve cover and investigate. Thanks All!!!
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Old 01-05-2013, 06:34 PM   #36
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Default Re: backfire

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Originally Posted by Rich in Tucson View Post
Check and then recheck your valve clearances. Five miles is plenty of time for heat to do its thang and permit an intake valve(s) that is/are set too tight to sit up off its seat and cause symptoms that you describe.
This may be the cause!!!!
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Old 01-05-2013, 06:37 PM   #37
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Default Re: backfire

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Originally Posted by Lycoming-8 View Post
Back many years ago I had a problem where the car would develop a very rough running condition, and loss of power after being run for about the same amount of time as you suggested in the first post. After going thru a similar list of parts replacements, an older fellow who ran a restoration shop suggested using some Bardahl. Couldn't find any, but did try some STP thru the carb. After three restarts, short drives, and cool-offs, the problem left and never came back. Final diagnosis was multiple stuck valves, once engine reached operating temp. If this is your problem, I would guess the number stuck is likely less than mine !!!
How did you put the stp thru the carb. its thick!!! This is our next test!!! Thanks.
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Old 01-05-2013, 07:07 PM   #38
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Default Re: backfire

Please keep us posted Gary, thanks.
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Old 01-05-2013, 08:31 PM   #39
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Default Re: backfire

As thick as STP is, I can't imagin it getting sucked up the intake and onto the valve stems. Sea-Foam is a good solvent and would be my first choice.

When I first saw STP, I thought maybe he meant LPS, but I guess not.
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Old 01-06-2013, 01:05 AM   #40
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Default Re: backfire

Ha, Ha, back in the day (early 60's), all of the fancy stuff of today was not available. So, yeah the STP wasn't easy. I made a 'dam' out of card-board that I could pour a little bit of the STP into and then close it up over the choke port. When the engine started to gag, I'd open it up a bit and let it breathe. Then repeat it again and again till I had about 3/4ths of the can into and thru the carb. The remainder went into the crankcase. This was one case where a downdraft carb would have been helpful.
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