The Ford Barn

ford38v8 · 08-30-2025, 01:27 AM

Kev, I'm no expert at these issues, not by a long shot, but I do thank you for the detailed list of what you have to work with that the real experts can go with. I have, however, picked up on a couple things that may be worth investigating:
1 - you mentioned the vacuum brake and piston, but had nothing to say about it's leather seal atop that piston and it's rub on the advance disc. That seal does double duty, one to seal the vaccum, and two to dampen the disc. Back in the day with low octane fuel, adjustment of that damper was critical to prevent ping, but with today's fuel, its main purpose is to prevent wild bouncing of the advance disc. Adjustment to provide that dampening effect may be fruitful: A leather softened with oil, turned to a fresh rub spot, and cranked in enough to stabilize but not immobilize is good.
2 - The shaft binding on the disc is a no brainer, I assume you've gotten that issue taken care of.
3- You may have done this already, but try running the Bosch pump continuously for a test run, but only if you have a proper pressure regulator in the system. your stated 2 ½ lbs is perfect, but is it consistent? A related issue can be checked if when it suddenly dies with apparent fuel loss, immediately remove the air horn to check the fuel level at engine shut-down. I say immediately because a hot engine will rapidly evaporate the fuel from the bowl. There was a neat KRW visual bulb external to the bowl, but I believe it proved unreliable due to strong under-hood air currents.
Again, just the village idiot here, so what do I know?

08-30-2025, 01:27 AM	#11
ford38v8 Senior Member Join Date: Jul 2011 Location: SF Bay Area Posts: 7,634	Re: Ignition Issues, Crab distributor Kev, I'm no expert at these issues, not by a long shot, but I do thank you for the detailed list of what you have to work with that the real experts can go with. I have, however, picked up on a couple things that may be worth investigating: 1 - you mentioned the vacuum brake and piston, but had nothing to say about it's leather seal atop that piston and it's rub on the advance disc. That seal does double duty, one to seal the vaccum, and two to dampen the disc. Back in the day with low octane fuel, adjustment of that damper was critical to prevent ping, but with today's fuel, its main purpose is to prevent wild bouncing of the advance disc. Adjustment to provide that dampening effect may be fruitful: A leather softened with oil, turned to a fresh rub spot, and cranked in enough to stabilize but not immobilize is good. 2 - The shaft binding on the disc is a no brainer, I assume you've gotten that issue taken care of. 3- You may have done this already, but try running the Bosch pump continuously for a test run, but only if you have a proper pressure regulator in the system. your stated 2 ½ lbs is perfect, but is it consistent? A related issue can be checked if when it suddenly dies with apparent fuel loss, immediately remove the air horn to check the fuel level at engine shut-down. I say immediately because a hot engine will rapidly evaporate the fuel from the bowl. There was a neat KRW visual bulb external to the bowl, but I believe it proved unreliable due to strong under-hood air currents. Again, just the village idiot here, so what do I know? __________________ Alan