Back Firing

[ssl78]

bad diverter valve or vacumn signal

[Salvatore]

John, What car did you buy? Any pictures? Sam

[1randy]

Possible exhaust leak

[sg1747]

http://i708.photobucket.com/albums/w...7/DSCN2120.jpg

[jtower1969]

I'm no expert....but I would vote for lean. Colder temps have more oxegen in the air...you need to put more fuel in the carb to equal this out. I have a baseline for my car and adjust air bleeds up or down 1 1/4 turn before changing jets.

[Xplantdad]

I thought all smog set ups backfired to a point...which is one of the reasons that people took them off...

[napa68]

Judging by the hood, it's a cross ram. My vote, Too fat!
Excess fuel gets in the exhaust, A.I.R. does its job, wham...backfire! M.O.O. and $0.02
Tim

[wagonman]

[ QUOTE ]
Judging by the hood, it's a cross ram. My vote, Too fat!
Excess fuel gets in the exhaust, A.I.R. does its job, wham...backfire! M.O.O. and $0.02
Tim

[/ QUOTE ]

SOME WORDS OF WISDOM HERE!from the previous post.

Your car is backfiring from where?

Intake? or Exhaust?You didnt specify,but i know by experience that your talking about backfiring out your exhaust.When your throttle plate is closed under your extreme high vac conditions as you described.Your engine is backfiring from either experiencing a very rich air/fuel condition or an exhaust leak,bad diverter valve.During this period of deceleration,are you experiencing plumes of black smoke from your tailpipes?(RICH)

Generaly speaking:

"Backfire" is popping through the carb.....usually due to a lean condition caused by improper air/fuel ratio and or timing.


"Afterburn" or backfiring through the exhaust is caused by an excessively rick air/fuel ratio and or timing.

[Salvatore]

NIZZZE car John!

[sg1747]

i wish it was a cross ram.wens i will block up all the holes in the exhaust manifold and try that.

john