B-67 Stalling After Roughly 30Min

[atcpete2701]

1964 b-67 non turbo. truck will run awesome and drive great for about 1/2 hour. Then it will start to sputter like its running out of fuel, then eventually die, we have to wait about 20 mins, then bleed air out of the injection lines (sometime it will just fire right up without bleeding), then she fires up and runs pissa for another 30mins. I figure its sucking air but all the lines seem fine and if it were sucking air I figure it would only run for a min or 2. What else could it be? Truck has only 155k on it and its a very clean motor, pump was never turned up or fooled with. Thanks for any ideas in advance! -Pete

[Rob]

1964 b-67 non turbo. truck will run awesome and drive great for about 1/2 hour. Then it will start to sputter like its running out of fuel, then eventually die, we have to wait about 20 mins, then bleed air out of the injection lines (sometime it will just fire right up without bleeding), then she fires up and runs pissa for another 30mins. I figure its sucking air but all the lines seem fine and if it were sucking air I figure it would only run for a min or 2. What else could it be? Truck has only 155k on it and its a very clean motor, pump was never turned up or fooled with. Thanks for any ideas in advance! -Pete

Sounds like you are on the right track with air in the lines. I would replace the rubber line with a copper running from the tank to the transfer pump and see if the problem still exists. Those old rubber lines can minutely crack and you will never see it. Since this section of line is under negative pressure, (vacume) it may not leak fuel, or seep. The fittings on both ends are 45 degrees, so regular plumbing fittings for a test case will work.

Rob

[b61fred]

Hi,

The way I inspect for air leaks in the vacuum side of the system. remove the line at the pump and make a line that is a foot or so long that is clear. I have used vynyl hose from the hardware store. connect the clear hose between the pump and the supply line you remove earlier. start the truck and check for air bubbles is the line, if you have bubbles then you need to find the source of the air. If there is no bubles but no fuel, inspected the rubber lines for collapsed internal liners.

b61 Fred

[hlane3]

1964 b-67 non turbo. truck will run awesome and drive great for about 1/2 hour. Then it will start to sputter like its running out of fuel, then eventually die, we have to wait about 20 mins, then bleed air out of the injection lines (sometime it will just fire right up without bleeding), then she fires up and runs pissa for another 30mins. I figure its sucking air but all the lines seem fine and if it were sucking air I figure it would only run for a min or 2. What else could it be? Truck has only 155k on it and its a very clean motor, pump was never turned up or fooled with. Thanks for any ideas in advance! -Pete

[hlane3]

Check for a plugged vent in your fuel tank.

[WHITE9064TD]

Could you have "junk" in the tank that takes 1/2hr finally to block off the inlet. Just something to check.

[theakerstwo]

Another thing to check and i have seen this on cats in most cases but can happen to a mack.Check when running the return line at the tank and make sure it is returning. The deal is if it can not return it can build up air in the galley of the fuel pump and stall just like it was sucking air. All fuel injectors will to some degree pass some compression back into the return fuel to the tank. But on that system there the return from the injectors is after the pressure ruglator valve so the only way air can get back to the pump is if a injector is not checking compression and the deliver valves in the top of the pumps are not holding and ten it can build up. Maybe not but i would check it.The sight glass that was spoke of is a must.