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Discussion Starter #1
Driving home from work this evening, my car backfired loudly while accelerating in first gear and died. I had to get it towed home. It will crank over fine, but will not start. I lined up my timing marks and pulled the dizzy cap, the rotor is pointing 60 degrees or so from #1. I rotated the engine over by hand one revolution just to make sure I wasn't 180 out. The rotor is now 60 degrees or so the other way from #1. I know the dizzy didn't move, the vacuum advance is still pointing straight ahead. So what happened? timing chain? This is a 351w with maybe 10,000 miles on the rebuild with everything being new at the time of rebuild. The engine has run flawlessly since the rebuild. Could it be something in the distributor?
 
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That happened to me going down the highway. I was the roll pin in the distributor gear, it sheared in half and spun the gear on the shaft. I was told that do to the fact that I had just rebuilt my 351-W with a high volume oil pump, that would cause it to snap cause the factory pins are weak and don't hold up well to the better pumps. I just replaced it with a new larger diameter one and was on my way. No problems since then.
 

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Another reason,...

Oil pump lockup (debris in pump?) caused you to shear the roll pin holding the distributor gear in place. (Usually wraps up the oil pump driveshaft into a nice pretzel but I've seen it shear the pin. It's sometimes hard to see because externally the pin is still in the gear but it will spin on the shaft)
 

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Pull the distributor and looking down the hole see if the cam turns. If yes, check the distributor, gear etc. If no, pull the front cover. At tenK miles I'd dought the timing chain has worn out, more likely the cam gear fell off the front of the cam because the bolt wasn't LocTited and wasn't torqued properly. Install a new timing chain and both gears as you don't know if those ones got tweaked or not.

If you check the disrtibutor and don't find a problem, even if the cam turns, the timing chain is likely to have jumped time and is still the problem.
 

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Discussion Starter #7
If I sheared the pin, would I be able to grab the rotor and spin it? The rotor does turn when cranking the engine.
 

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It's possible you could turn the shaft. You might need to remove the rotor because it will probably take more effort if the pin is sheared though. Remember, your turning the oil pump too when you turn it....
 
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