Ok so I have got my rebuilt 302 to really smooth out and run pretty good with y'alls help, which is greatly appreciated. Now a new problem that is completely stumping me has arose. I set my initial timing to 10-12*, if I hit the throttle the timing will advance (like it should) but it stays advanced, like 18-20* advanced. ( not the throttle return spring, I checked by pressing back directly on the linkage and it doesn't move any further back or change the timing) This is without the vacuum advance hooked up, if I hook that up it jumps to about 30-32*. she runs fine throughout the advancing but just this afternoon I went to fill the truck with gas, first trip longer than around the block, and she wouldn't start after shutting it off. she had a super slow cranking that eventually just wouldn't turn. Had to let it sit for about 2-3 hours but when I went back she fired right up. It seems like heat soak or something of the sorts but with the timing issue, I think there is more to it. I have new wires from bat to ground and starter solenoid, new solenoid, new starter, new distributor, new coil, pretty much everything in the engine bay is new. Anyone ever hear of this and have a solution? Like I said I am lost. Thanks, DJ

 

With the vacuum advance disconnected and plugged, factory idle RPM, you have it set at 10 to 12, sounds good.

Being careful of the plane of the fan blades, when you run it up through 1k, 2k, 3k, etc you should see it advance smoothly on the damper and will probably exceed 36 or 38 degrees if it is a stock distributor.

What you are saying, is once it advances along with the RPM, it never snaps back to the base crank timing of 10 to 12? That can only be a defective distributor mechanical advance if this is the case. It would in turn also make starting very difficult as excessive timing will cause kickback.

 

Agree with Tedster9. You might want to pull the mechanical advance cams or weights and check/clean them out. Check the springs in there, too. Make sure the breaker plate is not loose.

 

Thanks for the replies. That's what I was leaning towards but with it being a brand new distributor, knowing pretty much all car parts these days are lower quality, I wanted to see others opinions before I pull it and get another one on warranty. Thanks again and please if anyone else has a different thought, post it up incase this doesn't work. - DJ

 

They are fairly simple it may just need the breaker plate to be secured or, it's sticking. Worth going through it and determining the source of the problem, though can't think of what else it would be. Maybe take some pics so we can take a looksee.

 

A way to check if it is the advance mechanism is to run the motor up to temp, then shut it off. Try cranking it, if its slow then disable the ignition from producing spark and try again. If it now spins like it does cold, then it is a timing advance issue. If it still turns slow, then its either the motor is tight or there is heat soak in the starter which increases the winding resistance and makes it crank slow. Just be careful how you disable the spark if its a Duraspark module, you should either pull the coil wire and terminate the lead in a spark tester or pull the plug at the module that supplies 12v.