[ron]

WHAT DO YOU THINK IS THE PROBLEM?
WAS DRIVING TO WORK THE OTHER MORNING WAS DOING ABOUT 80 MPH THINKING THAT THE CAR WAS RUNNING GREAT, LET OFF THE GAS TO EXIT TO THE DECELLERATION RAMP, WAS DOING ABOUT 55 WHEN THE ENGINE BACK FIRED SO MUCH SO THAT I THOUGHT I BLEW OUT THE EXHAUST. CAR ACTULLY SHUT DOWN AND RESTARTED BECAUSE OF THE SPEED, SINCE THEN THE ENGINE HAS A MISS THATS DRIVING ME NUTS.
ITS A REBUILT 351W 30 OVER EDELBROCK MANIFOLD AND CARB. PERTRONIC SYSTEM WITH A MSD 6A IGNITION, NEW WIRES ,BLASTER COIL, NEW STOCK DISTRIBUTOR,NEW CAB AND ROTOR. ALL VACUUM HOSES ARE NEW AND NEW TRANSMISSION MODULATOR. Im ready to shoot it and look for a mopar.
ANY SUGGESTIONS

 

[1965FALCON]

Well, since nobody else is guessing...

Check and make sure each cylinder is firing (pull the plug wires one at a time, you probably already did this) you might have some wires arcing, bad cap or rotor maybe. I'd look for any hairline cracks in the cap.

You might also have lost a spring in your distributor mechanical advance.

I'd look at the carb too, see if you blew out a seal or diaphram... etc.

well... there's a start!

 

[Just Strokin]

Would help if you gave more info on your diagnostics of your problem so far. Such as have you pulled the plugs and checked them, have you cehcked the oil for water or the water for oil, etc.....

 

[Troy Boswell]

Look at the electronics/timing first. Make sure the dizzy isn't moving or some other weird ****. Then, look at the carb. It may not hurt to take it off and blow it out with some carb cleaner. Maybe a chunk of crap is in the bowl floating around and messing with your jetting. Good luck.

 

[1970galaxie]

I agree with previous replies, check the little things first. The first thing to check would be the ignition wires. the vibrations of the car may have caused enough interuption of the current to cause the thing to backfire. Always try to look @ the basics before condemning parts.

 

[Timo]

You might also want to replace your pertronix with points and see if that cures your problem. Mine misses and it turned out to be the pertronix unit.

 

[Cyclone Joe]

I bet you fouled a spark plug, now you're only running on 7 instead of 8. I had a friend who's mustang did this, except at higher speed. It actually melted a good part of the plug. We tracked it down to a defective spark plug wire for that cylinder. Good luck