backfiring when I floor it???

[paul1966]

I have  a 66 charger with a 383/ 650 carb, 727 trans.  Drives wonderful at normal speeds, until I get on it. Not on the Highway, I am fine there, but when I floor it from a stand still, I get a little bog and then acceleration, and theni in between 1st and 2nd I get a bog down, and backfire.  Is the cause of this the carb?

Thanks Much
Paul

[Nacho-RT74]

it does look a carb issue... unless vacuum advance diaphragm is some worn.

Is just an opinion, I'm not the expert

[resq302]

I had a similar problem with my 70 El camino SS 396.  The carb was running fine then one day it started popping out through the carb, only on a full throttle acceleration from a dead idle.  Turned out the timing needed some fine tuning (not much) and the gas was down almost to empty.  I filled up with 93 octane and the problem went away instantly.

How old is your gas?

[doctorpimp]

Check your ignition.
I put all new plugs, wires, cap&rotor etc on an old car that I owned when I was in college.  About 3 months later it started sputtering under load and immediately I thought it was a fuel problem.  Eventually, I took it to a mechanic who in turn hooked it up to a fuel injection computer (it was FI  )  Nothing was wrong with my fuel, just a bad plug wire : It was the last thing I thought would go wrong, since it was only 3 mos old.

[Rolling_Thunder]

im having a similar issue  - just today i had a backfire at the top of 3rd gear...   only happens when im HARD through all the gears - it pops at the very top of 3rd - then it is fine