Backfiring and cutting out

[sandmanf250]

if it's backfiring out the exhaust it's probably ignition related.go back over your dist work check all wiring and connections then use a dwell meter to check your dwell after setting the points.also check your distributor cap on both the inside and out to look for hairline cracks and you might see signs of carbon tracking on the inside of the cap if it's old.

[Supermike]

I actually found some indications that backfiring can be caused by the coil, so you may be on to something, sandman... if it's coming from the exhaust and not the carb, it may not be a fuel flow problem UNLESS maybe raw fuel is getting into the exhaust lines and igniting there...

[sandmanf250]

that wouldn't have anything to do with an additive in the oil that i can think of. you were in that distributor so i'm thinking electrical.check her over real good.if raw gas is getting to the exhaust system it's because it didn't fire in the cylinders.good luck

[ArizonaDan]

What causes backfiring in the exhaust:

Would it be the air/fuel mixture actually igniting in the exhaust manifold rather than the combustion chamber or,

Would it be the air/fuel mixture igniting in the combustion chamber but with the exhaust valve open?

I can conceive that if an air/fuel mixture was not igniting (dead cylinder) then the unburned air/fuel mixture would be pushed into the exhaust manifold where it could ignite when exposed to the hot air and metal of the exhaust manifold/header.

I can also conceive that if the ignition timing was late that the combustion process would still be in progress when the exhaust valve was opened which would allow high cylinder pressure to escape into the exhaust manifold/header which would cause the effect of an exhaust backfire.

Which scenario is more likely or are they both equally common?

Causes of a "Dead cylinder" -bad spark plug, bad plug wire, bad rotor, bad distributor cap, weak coil, weak ignition voltage, low compression, bad points, defective timing advance, incorrect base timng, incorrect firing order,weak or broken valve springs, bad lifters or any combination of above factors.

Good luck

[soulcrushing71]

I had the exact same problem you are describing, turns out I had a worn out distributer that was causing all my stuttering and backfires. Had a new distributer put in with an electronic ignition, and it runs badass now.

[Always Learning]

So I took a look at the timing based on the timing marks on the harmonic balance. I aligned the timing mark and opened the distributor cap and found that the rotor was about 90 degrees off. Instead of pointing to the #1 cylinder(most forward on passenger side) it is pointing to the 3rd back on the drivers side, so that would be #6 or 7.
Could this have happened without someone removing the distributor? I have never pulled it.
How do I go about getting it back in alignment?

[fordman]

the dist will turn around once for the damper twice. so if you roll it over one more time it should be on the marks on the damper and correct on the dist. if that isnt the problem the timing chain could have jumped. but it would be hard for it to jump exactly 180 out.