injector pump advice

[JoeIsuzu]

I'd be tempted to rig up a temporary "tank" using an oil jug or similar, to see if it loses prime.

Jack

[Paul]

I might add, at this point all of the soft lines have been replaced, and I have a clear line on the feed to the filter.

once primed and running, I am getting a slow periodic group of bubbles coming in from the tank, seemingly they lessen and eventually dissapear,..only to lose prime again overnight.

You know, easy things first. Joeshmoe made a good suggestion up front - - 'Replace the fuel filter with a piece of fuel line and see what happens'.

This is easy and the fuel filter does have several places where it can leak.

If this doesn't work, then back to the tank. Since you have the bed off, you can attach your vacuum pump and bottle to the fuel outlet pipe and pump a bit. If you get clear fuel, no hole, no leak. If you get bubbles here, must have a leak in the tank.

Or, try what Jack has suggested. Also, not too hard to do.

Paul

[dorf]

What about fuel filter seals. Drain valve etc on the fuel filter sucking air

[swamp pup]

So,..I bypassed the filter and lost prime within a couple of hours.

reconnected the filter, even though I shouldn't rule that out as well

and stuck the soft pick up line from the top of the tank into a jug of fuel, making sure to keep the end well below the waterline overnight.

I eliminated the clear tygon lines altogether as they seemed to have lamination issues at the cut ends.
I can swap out for temporary vinyl if things persist

we shall see.

[swamp pup]

bypassed the tank, same issue
spoke to a local diesel mechanic and he told me it was probably the return hard line or connection, since we're not seeing fuel leaking anywhere
bypassing that now