I've been trying to resolve an intermittent problem with the fuel delivery on my 78 B motor. It's an intermittent problem what rears its head occasionally in two forms:
1) At idle it has almost died completely once or twice. Giving more pedal has resulted in it almost stalling out.
2) When running at faster speeds (4th gear) tilt I can sometimes hear it miss, usually when decelerating or at light throttle. It did it on the downside of along uphill run.
It only ever happens when the truck is warm. Idle is almost always smooth and at the same RPM.. Doesn't go up or down (except once when it gradually decreased and ran rough and stalled out. Once I started it, it idled perfectly again)
Any ideas? I've checked the fuel lines and haven't found any leaks. Fuel filter has been replaced. The fuel system has been primed repeatedly. I don't think that it’s the diaphragm because idle is relatively consistent. I was thinking it could be a vacuum problem until I had a look today and spotted a leak on the injector pump. Since diesel is getting out, I assume that means air can get in. I've looked through the archives but can't find the purpose of this screw. Can anyone tell me? Is this the drain screw at the bottom of the diaphragm?
1) At idle it has almost died completely once or twice. Giving more pedal has resulted in it almost stalling out.
2) When running at faster speeds (4th gear) tilt I can sometimes hear it miss, usually when decelerating or at light throttle. It did it on the downside of along uphill run.
It only ever happens when the truck is warm. Idle is almost always smooth and at the same RPM.. Doesn't go up or down (except once when it gradually decreased and ran rough and stalled out. Once I started it, it idled perfectly again)
Any ideas? I've checked the fuel lines and haven't found any leaks. Fuel filter has been replaced. The fuel system has been primed repeatedly. I don't think that it’s the diaphragm because idle is relatively consistent. I was thinking it could be a vacuum problem until I had a look today and spotted a leak on the injector pump. Since diesel is getting out, I assume that means air can get in. I've looked through the archives but can't find the purpose of this screw. Can anyone tell me? Is this the drain screw at the bottom of the diaphragm?