backfire through carb

streetstang88 · 11-23-2005, 01:20 PM

i know this is windsor tech ,and a 400 in a 1977 pick up is not windsor tech
but its close enough ......
i have a old wore out (most likely my problem) 400 in my 4x4 and it keeps
back fireing trough the carb even when @ idle ,it is sporatic , i have checked timeing,and fuel to make shure its not a lean out problem(new carb) ...seem to be ok

the only other things that i can think of is weak valve springs or maybe
some carbon build up ???? i am thinking of running massive amounts of
seafom through the carb and fuel and in the oil ....

any ideas ?????????

Italian LX · 11-23-2005, 01:24 PM

Quote:

Originally Posted by streetstang88

i am thinking of running massive amounts of
seafom through the carb and fuel and in the oil ....

That wouldn't be a bad idea.

streetstang88 · 11-23-2005, 01:27 PM

much more of it and my holley will be toast

Italian LX · 11-23-2005, 01:28 PM

What condition is your timing chain in. Maybe it has enough slack to retard your cam timing a considerable amount.

coupe · 11-23-2005, 01:32 PM

Carb could be shot or even bad EGR valve... But yea; most likely cam and/or ignition timing.

streetstang88 · 11-23-2005, 01:39 PM

that will be my next step if this dont work ....along w/ whole new top end

but first prodigious amounts of seafoam

Sendero · 11-23-2005, 08:43 PM

Uhhh, isnt a 400 a 351 block with a Modifed crank? That would make it a Windsor.

Sorry

QWKSNKE · 11-23-2005, 09:02 PM

Quote:

Originally Posted by Sendero

Uhhh, isnt a 400 a 351 block with a Modifed crank? That would make it a Windsor.

Sorry

No... 351-400 m's are not of the windsor family

coupe · 11-23-2005, 09:42 PM

It's a 351M-400 and it actually displaces 400"
It's a cleveland motor. My buddy's '78 T-bird had one with a 2-bbl.
Whatta pile of junk.

1Quik85GT · 11-23-2005, 09:53 PM

check the power valve..

11-23-2005, 01:20 PM	#1
streetstang88 Senior Member Join Date: Jul 2005 Location: confusion Posts: 184	backfire through carb i know this is windsor tech ,and a 400 in a 1977 pick up is not windsor tech but its close enough ...... i have a old wore out (most likely my problem) 400 in my 4x4 and it keeps back fireing trough the carb even when @ idle ,it is sporatic , i have checked timeing,and fuel to make shure its not a lean out problem(new carb) ...seem to be ok the only other things that i can think of is weak valve springs or maybe some carbon build up ???? i am thinking of running massive amounts of seafom through the carb and fuel and in the oil .... any ideas ????????? __________________ '89 LX 5.0 Hatchback (light blue metallic) t-5 ,traction lock ,high volume fuel pump underdrive pulleys, chip NEEDS MORE COWBELL

11-23-2005, 01:27 PM	#3
streetstang88 Senior Member Join Date: Jul 2005 Location: confusion Posts: 184	Re: backfire through carb much more of it and my holley will be toast __________________ '89 LX 5.0 Hatchback (light blue metallic) t-5 ,traction lock ,high volume fuel pump underdrive pulleys, chip NEEDS MORE COWBELL

11-23-2005, 01:28 PM	#4
Italian LX Daddy x4 ...we're done Join Date: Dec 2004 Location: Oxford, AL Posts: 11,551	Re: backfire through carb What condition is your timing chain in. Maybe it has enough slack to retard your cam timing a considerable amount. __________________ -Brian '86 Mustang GT Convertible '88 Mustang LX coupe '11 Odyssey TE '21 Insight Touring

11-23-2005, 01:32 PM	#5
coupe Super Moderator Join Date: Dec 2004 Posts: 6,313	Re: backfire through carb Carb could be shot or even bad EGR valve... But yea; most likely cam and/or ignition timing. __________________ " If you can't explain it simply, you don't understand it well enough. " - Albert Einstein

11-23-2005, 01:39 PM	#6
streetstang88 Senior Member Join Date: Jul 2005 Location: confusion Posts: 184	Re: backfire through carb that will be my next step if this dont work ....along w/ whole new top end but first prodigious amounts of seafoam __________________ '89 LX 5.0 Hatchback (light blue metallic) t-5 ,traction lock ,high volume fuel pump underdrive pulleys, chip NEEDS MORE COWBELL

11-23-2005, 08:43 PM	#7
Sendero Im gonna show her my... Join Date: Dec 2004 Location: Somewhere providing FREE tech support. Posts: 4,269	Re: backfire through carb Uhhh, isnt a 400 a 351 block with a Modifed crank? That would make it a Windsor. Sorry __________________ I heard it on the internet, so it must be true. "I believe that a person's moral compass can be determined by how he references free men the right to defend themselves." T. Nugent "An armed society is a polite society. Manners are good when one may have to back up his acts with his life." R. Heinlein "Never argue with an idiot. They drag you down to their level, then beat you with experience." -Unknown

11-23-2005, 09:42 PM	#9
coupe Super Moderator Join Date: Dec 2004 Posts: 6,313	Re: backfire through carb It's a 351M-400 and it actually displaces 400" It's a cleveland motor. My buddy's '78 T-bird had one with a 2-bbl. Whatta pile of junk. __________________ " If you can't explain it simply, you don't understand it well enough. " - Albert Einstein

11-23-2005, 09:53 PM	#10
1Quik85GT Senior Member Join Date: Apr 2005 Posts: 895	Re: backfire through carb check the power valve..