Engine Running Rough

[Mick Blake]

Engine runs fine at idle,vaccum gauge reads 19. When throttle opened engine runs very rough and backfires. I have tried changing carbs and distributors, nothing helps.Anyone run into this problem? Thanks:

[Reg Evans]

I'm having the very same problem. I suspect it's the dist. or vacuum advance so I am going to replace them with a HEI unit. Hope that does the trick.

[MBF]

You could have some slow valves that are starting to hang too. Try giving it a dose of Marvel Mystery oil down the throat of the carb with it revved slightly. Just some advice-don't do this near an open window, or inside a building.

[Dodgeb4ya]

You might think to rotate the crank back and forth to check for a sloppy timing chain, causing slow valve timing. Watch the rotor to see if it is tight to crankshaft forward and backward movement of the crank.

Bob

[Mick Blake]

Found the problem, installed new ignition cables, runs fine. Thanks

[bach4660]

with new wires what do you read on the vacuum gauge?

[Mick Blake]

The reading is 19.

[1949P17BC]

Got here late but I would have recommended changing the wires, starting with the coil. Been there done it

[norrism1]

Just to let you know, The capacitor in or on the distributor may be weak. When high load is put on it during rev it can "leak" and cause the enginge to stumble causing the backfire. Just something to look at next time. My 2 cents.

[Mick Blake]

Just to let you know, The capacitor in or on the distributor may be weak. When high load is put on it during rev it can "leak" and cause the enginge to stumble causing the backfire. Just something to look at next time. My 2 cents.

You are right,that was also part of the problem.