• Mustang Forums
  • 1965 - 1973 Classic Mustangs -General/Talk-
  • Classic Mustang Specific Tech

Odd fix for backfiring through the carb

  • Thread starter Thread starter hunterhicks
  • Start date Start date Jul 22, 2007
H

hunterhicks

Member
Dec 4, 2003
62
0
7
D/FW
Jul 22, 2007
#1
  • Jul 22, 2007
  • #1
FYI for those good kiddies that use the search feature of this site.

I had a really odd problem of backfiring through the carb when I put any load on the engine- you could drive, but you have to very slowly accelerate or POP POP goes the carb.

Edelbrock 600 1406. I totally rebuilt the carb, changed timing, changed rods and jets, you name it. nothing fixed it.

What was it?

The ignition. I had a bad plug/wire/cap/rotor- not sure which, replaced all of them at once, and it is now fixed.

Strange, eh?
 

68keyblr

20+ Year Stangneter
Mar 17, 2003
946
20
49
Arizona
Jul 23, 2007
#2
  • Jul 23, 2007
  • #2
hunterhicks said:
FYI for those good kiddies that use the search feature of this site.

I had a really odd problem of backfiring through the carb when I put any load on the engine- you could drive, but you have to very slowly accelerate or POP POP goes the carb.

Edelbrock 600 1406. I totally rebuilt the carb, changed timing, changed rods and jets, you name it. nothing fixed it.

What was it?

The ignition. I had a bad plug/wire/cap/rotor- not sure which, replaced all of them at once, and it is now fixed.

Strange, eh?
Click to expand...

It was most likely the cap...there was probably a short that was causing a cylinder to fire when an intake valve was still open.

I had similar behavior when I got some condensation under the cap...I was lucky, I simply dried it off and it worked fine.

It's always a good feeling to solve one of those pesky problems, eh?
 
D

D.Hearne

New Member
Sep 29, 2000
11,730
6
0
south louisiana
Jul 23, 2007
#3
  • Jul 23, 2007
  • #3
Nothing odd about it, what often seems like a carb or fuel problem can just as likely be ignition related.
 
O

oscart

New Member
Sep 6, 2006
19
0
0
Jul 24, 2007
#4
  • Jul 24, 2007
  • #4
Back firing through the carb often means that the timing is too far advanced. Back firing in the muffler can mean the timing is far retarded. Also, check your firing order and the condition of your wires. In the dark of the night run your car with the hood up and with a spray bottle, mist warm water over the engine and watch for sparks or arching.
 
D

D.Hearne

New Member
Sep 29, 2000
11,730
6
0
south louisiana
Jul 24, 2007
#5
  • Jul 24, 2007
  • #5
Thru the carb also happens with retarded timing. If it's retarded enough, it'll hiccup thru the carb when you try to accellerate too fast from a stop
 

Max Power

Active Member
Jul 31, 2003
1,774
1
36
St Paul
Jul 24, 2007
#6
  • Jul 24, 2007
  • #6
So, when I get a backfire, replace the entire ignition system?

Got it!

 
D

D.Hearne

New Member
Sep 29, 2000
11,730
6
0
south louisiana
Jul 24, 2007
#7
  • Jul 24, 2007
  • #7
Yea, but you also need to upgrade the intake and carb too!!!!!! No sense wasting that money.
 

Bosscat

Founding Member
Sep 30, 1999
1,265
0
0
England
Jul 25, 2007
#8
  • Jul 25, 2007
  • #8
hunterhicks said:
FYI for those good kiddies that use the search feature of this site.

I had a really odd problem of backfiring through the carb when I put any load on the engine- you could drive, but you have to very slowly accelerate or POP POP goes the carb.

Edelbrock 600 1406. I totally rebuilt the carb, changed timing, changed rods and jets, you name it. nothing fixed it.

What was it?

The ignition. I had a bad plug/wire/cap/rotor- not sure which, replaced all of them at once, and it is now fixed.

Strange, eh?
Click to expand...


Good info!
 

mustangmike6996

5 Year Member
Nov 10, 2005
483
6
29
clinton twp, MI
Jul 26, 2007
#9
  • Jul 26, 2007
  • #9
CARBON TRACKING

its when carbon builds up on the bottom of the cap and creates an easier electrical path to be completed by the ignition system.. then it fires on the incorrect plug... pretty simple sometimes it is very hard to see.. if you still have the old parts look under the cap for a tiny black line that looks similar to a "lightning bolt" shape thats normally the path it would take
 
You must log in or register to reply here.

Similar threads

D
Engine 85 GT Backfires through Carb
  • DienstXIV
  • Oct 3, 2025
  • Fox 5.0 Mustang Tech
Replies
19
Views
591
Fox 5.0 Mustang Tech Oct 7, 2025
85GTStangGuy
A
95 Gt intermittent backfire
  • A_A_Ron
  • May 26, 2025
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
Replies
0
Views
402
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- May 26, 2025
A_A_Ron
A
Engine 1990 LX 5.0L EFI Mustang Fuel Management Problems - HELP!
  • 5.0LXStanger
  • May 25, 2025
  • Fox 5.0 Mustang Tech
  • 2 3
Replies
45
Views
2K
Fox 5.0 Mustang Tech Jul 11, 2025
5.0LXStanger
Drivetrain 83’ Glx convertible C5 Trans help!
  • JacksonJared2113
  • Dec 25, 2025
  • Fox 5.0 Mustang Tech
Replies
2
Views
339
Fox 5.0 Mustang Tech Dec 26, 2025
JacksonJared2113
R
1974 Datsun 620 pickup / 5.0L HO
  • RJH46
  • Aug 24, 2025
  • Other Auto Tech
Replies
1
Views
207
Other Auto Tech Aug 24, 2025
Noobz347
Share:
Bluesky Email Share Link
  • Mustang Forums
  • 1965 - 1973 Classic Mustangs -General/Talk-
  • Classic Mustang Specific Tech
Menu
Log in

Register

  • Forums
  • What's new
  • Media
  • Resources
  • Contact
  • Sponsor
X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?

X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?