Fuel problems. 77 1750 DV550

[ibendem]

I have recurring fuel delivery problems on my 1977 1750 Loadstar with a DV550. The truck may start and run, however, air intrusion appears to be occurring causing the engine to starve for fuel and attempt to die. Someone has plumbed an electric fuel pump inline between the tank and primary fuel filter. Activating the pump with the factory "primer" switch keeps the engine running but is a pain. I've replaced both fuel filters and dropped and cleaned the tank (which was already impeccably clean). The suction line inside the tank appeared to be solid, with no holes to suck air. I'm curious if anyone has experience as to where I should start searching for air intrusion. I'm guessing either a cracked rubber line or a fitting with the rubber sealing ring that has broken down. I'm contemplating application of low pressure air to the fuel tank to accentuate the leak. Any advice is appreciated. Thanks

[acem]

I was having no end of fuel problems with the fuel line on my 74 loadstar sv345. I replaced the fuel line between the tank and fuel pump and cured that problem. I just used rubber fuel line instead of metal.

[td9inidaho]

Is the electric pump inline?  Is it on at all times as the ignition?  I had similar situation on a tractor, is was the rubber lines to and from the inline electric pump, replaced those, life was good. My exp, you have to have the pump run all the time if inline, not sure they flow through very easily 

Mark

[ibendem]

I wondered about that. The pump is activated by the factory switch labeled "primer." It seemed to me the inline pump was a hillbilly way to fix a larger problem somewhere else. I may attempt to eliminate it.

[ibendem]

I wondered about that. The pump is activated by the factory switch labeled "primer." It seemed to me the inline pump was a hillbilly way to fix a larger problem somewhere else. I may attempt to eliminate it.