Bronco Hut  
 

   Ford Bronco Parts - Classic Vintage Early Bronco Parts   Toms Bronco Parts   BC Broncos
Community
 Message Forum
 Photo Gallery
 Event Calendar
 Book Reviews
 Bronco Wallpaper
 Bronco FAQ
 
 600+ Bronco Links!
 
Search all Bronco Links
Buy / Sell
 Classifieds / Want Ads
 Vendor Forum
Rust Bullet
Bronco Tech
Recent Tech Articles
 •Holley Carb Tips
 •Aussie Locker
 •C6 203 205 Doubler
 •4 Link
 •Clutch Replacement
 •Early Turn Signals
 •C4 Improvements
 •Threaded Dipstick
 •NV3550 5 spd
     More Tech...
Bronco Auctions

Welcome to the ClassicBroncos.com Forums.

You are currently viewing our boards as a GUEST which limits your access to viewing only. To take advantage of all the forum features please take a moment to register. Registration is fast, simple and absolutely free so please, join our community today!

If you have any problems with the registration process or your account login, please contact contact the admin. If you've lost your password click here.

Go Back   ClassicBroncos.com Forums > Archives > Bronco Tech - Archives

 
 
Thread Tools
Old 05/25/09, 05:53 AM   #1
Ethansdad73
Bronco Guru
 
Ethansdad73's Avatar
 
someone play a country song backward so i can get everything i have lost back...

Melbourne, FL
Joined: Apr 08
Posts: 1,383
backfire thru the carb ...solved

Ok i have had this happen once in a while and because the bronco sat for the last 4 years with out running i thought that it may have bad gas in it. I have now run both tanks 2x. (12/24) I still have this problem. It runs fine for a while then is feels like its missing and then "foomp" backfires thru the carb. My 302 has new plugs, new painless rewire, and new edelbrock carb, new cap and rotor, wires have very few hours on them, but are at least 8 yrs old I do also run headman heders. I am in FL and I do drive in the beautiful weather we have down here, it only been in the mid 80s +/- this last week so. I do feel that my bronco runs a little hot, I still need to get to the parts store and get a 190* stat.

So i know that i could start with new wires and stat, but what could be the issue? Any help would be apreciated, and thanks in advance for your help.

Last edited by Ethansdad73; 05/09/10 at 11:55 AM..
Ethansdad73 is offline  
Old 05/25/09, 06:13 AM   #2
6daze
Contributor
Sr. Member
 
6daze's Avatar
 
San Diego
Joined: Feb 07
Posts: 771

My Gallery
It was always a timing issue for me when this happened. Check that first.

6daze is offline  
Old 05/25/09, 06:17 AM   #3
Ethansdad73
Bronco Guru
 
Ethansdad73's Avatar
 
someone play a country song backward so i can get everything i have lost back...

Melbourne, FL
Joined: Apr 08
Posts: 1,383
What is a 302 w/ c4 suposed to run at?
Ethansdad73 is offline  
Old 05/25/09, 06:40 AM   #4
TBS-POPS
Bronco Guru
 
TBS-POPS's Avatar
 
ALL my drinking buddies have a severe bronco problem!!

valley springs, ca
Joined: Jun 07
Posts: 1,388

My Gallery
Water temp wise,,,,,180*.. A couple of things to check on your backfire,,, timing,, make sure the vacume advance is working,, clean out the carb. Edelbrocks are fussy about the least ammount of crap in them...I love mine but when it gets stuff in it, it will make things run really weird...

WWW.NORCALBRONCOS.COM 72, TBI 302, 435,20,FW44&9,4.56 w/pl&arb,2" & 5.5" on 37's.SOLD Broncoless for now
Broncos are like BOOBS, There always better after they've been worked on..
TBS-POPS is offline  
Old 05/25/09, 07:27 AM   #5
broncnaz
Contributor
Bronco Guru
 
I.Y.A.A.Y.A.S.

Thatcher, AZ
Joined: May 03
Posts: 22,382
X2 on the timing. While stock setting is about 6 degrees you can usually run more without issue. Id shoot for 10-12 just get as much as you can without the back fire. Another thing that could cause it is that the engine is not fully warmed up and the choke is still not fully opened so when you try to jump on the throttle it back fires.

73 Ranger 2 1/2 lift 302 TFS heads NP435,PS,PDB, tierod over, 33x10.50x15 BFG M/T
71 Sport 63,000 miles all orginal except for cut fenders 302 3sp 4.11's D44/BBTrac lok rear
broncnaz is offline  
Old 05/25/09, 08:56 AM   #6
markperry
Contributor
Bronco Guru
 
markperry's Avatar
 
Rock Chalk

Platte City
Joined: May 09
Posts: 3,893

My Gallery
I had this problem with back firing. Check your fuel pressure, if the engine is not getting enough fuel it will pop and sputter. I have a transparent fuel filter and noticed the fuel flow was very weak, so I went to Oreilly and bought a new fuel pump and replaced the fuel lines and the problem was solved. I saved some money by bending my own fuel lines, the whole project cost 41.00. Now it runs great again!
markperry is offline  
Old 05/25/09, 09:04 AM   #7
Steve
Bronco Guru
 
Steve's Avatar
 
GOT MOAB?

Grand Junction, CO
Joined: May 03
Posts: 2,986

My Gallery
As others have said it's probably a timing issue. It could also be running lean, which is NOT a good thing. Worst case it could be an intake lobe on the cam going flat, but since it's an intermittent thing that's probably not the problem.

69 narrowed 8 inches, locked F&R, big tires, EFI, Atlas, winch, blah, blah, blah
Steve is offline  
Old 05/25/09, 09:31 AM   #8
Amac70
ME
 
Amac70's Avatar
 
back on the trail

St Helens, Or
Joined: Mar 02
Posts: 3,077

My Gallery
Garage
One other thing to check is firing order if you have 2 wires switched it will still run but it will back fire through the carb to.

70' 351 efi w/fw d44/9 airlockers f/r,4r70w, oba, other stuff
Amac70 is offline  
Old 05/25/09, 09:48 AM   #9
blubuckaroo
Contributor
Bronco Guru
 
blubuckaroo's Avatar
 
Ridgefield WA
Joined: Jun 07
Posts: 6,434

My Gallery
After it goes foomp! does it die or does it keep running? Is this at idle or cruising? What kind of ignition set-up?

'77. 2" suspension lift, 1" body lift, 32" tires. 302, Windsor Jr heads, 4bbl, headers. NV3550, 4.11s, Yukon posi.
Vintage Air, Pioneer tunes, Toms seats.
All the comforts!
blubuckaroo is offline  
Old 05/25/09, 09:51 AM   #10
broncomitch
Bronco Guru
 
broncomitch's Avatar
 
dont be a sheep in a jeep!

west jordan, utah
Joined: Jan 08
Posts: 2,340

My Gallery
your carb could not be sealed properly with the manifold, could very well be timing. dose it happen when it gets hotter? check your points. they go bad easy.

might want to clean the carb. (never know how dirty those tanks where) could be you have a bad valve to.
or a simple gaskit leak. start with timing and go from there.

also look at your plug wires, see if there close or touching a exhaust manifold or getting hot when its running. could be arching on the motor causing it to miss fire or not get enough spark.

1971 bronco sport,mild built 351w,c6,strong box,np205,HP Dana60,srw 14bolt,disc's front and rear,16"rock coil overs,H1's & 44" tires,4.10's,3link front,56" springs,ez wiring,tbird EFI
Utah bronco club member
Build thread
http://classicbroncos.com/forums/sho...d.php?t=196087
broncomitch is online now  
Old 05/25/09, 10:04 AM   #11
Ethansdad73
Bronco Guru
 
Ethansdad73's Avatar
 
someone play a country song backward so i can get everything i have lost back...

Melbourne, FL
Joined: Apr 08
Posts: 1,383
Quote:
Originally Posted by broncnaz View Post
X2 on the timing. While stock setting is about 6 degrees you can usually run more without issue. Id shoot for 10-12 just get as much as you can without the back fire. Another thing that could cause it is that the engine is not fully warmed up and the choke is still not fully opened so when you try to jump on the throttle it back fires.
...

this usally only happens when warm mand have been driving a while
Ethansdad73 is offline  
Old 05/25/09, 10:05 AM   #12
Ethansdad73
Bronco Guru
 
Ethansdad73's Avatar
 
someone play a country song backward so i can get everything i have lost back...

Melbourne, FL
Joined: Apr 08
Posts: 1,383
Quote:
Originally Posted by markperry View Post
I had this problem with back firing. Check your fuel pressure, if the engine is not getting enough fuel it will pop and sputter. I have a transparent fuel filter and noticed the fuel flow was very weak, so I went to Oreilly and bought a new fuel pump and replaced the fuel lines and the problem was solved. I saved some money by bending my own fuel lines, the whole project cost 41.00. Now it runs great again!
That was the other thing that was new... the fuel pump and filter... but the carb was an out of box instal so i may be running lean...
Ethansdad73 is offline  
Old 05/25/09, 10:13 AM   #13
Ethansdad73
Bronco Guru
 
Ethansdad73's Avatar
 
someone play a country song backward so i can get everything i have lost back...

Melbourne, FL
Joined: Apr 08
Posts: 1,383
Quote:
Originally Posted by blubuckaroo View Post
After it goes foomp! does it die or does it keep running? Is this at idle or cruising? What kind of ignition set-up?
keeps on running thank God! im am usally running at 45-60 on the coast back and forth to my parents or to my inlaws house. At idle you can here a little mis. My ingition is a "SELECT" not sure who makes it... My coil is an excell.
Ethansdad73 is offline  
Old 05/25/09, 10:17 AM   #14
Ethansdad73
Bronco Guru
 
Ethansdad73's Avatar
 
someone play a country song backward so i can get everything i have lost back...

Melbourne, FL
Joined: Apr 08
Posts: 1,383
dose it happen when it gets hotter? yes
check your points. they go bad easy. -- they are new...could they go that quick they are only a month old

might want to clean the carb.... will do this.

getting hot when its running... im runningn headers they are hot...

could be arching on the motor causing it to miss fire or not get enough spark.../ they do cross eachother in a few places...
Ethansdad73 is offline  
Old 05/25/09, 10:18 AM   #15
Ethansdad73
Bronco Guru
 
Ethansdad73's Avatar
 
someone play a country song backward so i can get everything i have lost back...

Melbourne, FL
Joined: Apr 08
Posts: 1,383
While looking at my ingition i saw that my fuel filter is actually right above the manifold. could i be baking my fuel before it gets in the carb?
Ethansdad73 is offline  
 

  ClassicBroncos.com Forums > Archives > Bronco Tech - Archives

Thread Tools

Forum Jump


All times are GMT -6. The time now is 10:09 AM.


Bulletin Board Software by: vBulletin
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Garage Plus vBulletin Plugins by Drive Thru Online, Inc.


This site created, owned and maintained by Jon Hanna
Copyright 1996-2014 All rights reserved. Privacy Statement
ClassicBroncos.com is not affiliated with Ford Motor Company