I can't get the air out of the primary fuel filter. I've searched and tried every trick in the book(and on this site). New lines, remote fuel source, cracked injector lines, and I can't get the air out.
I think it's the primer pump, it pumps fuel in when I push down on the knob, but I think it's letting air in as well, cause after it's primed and only one air bubble remains in the filter and the car is running ok. I rev it a few times or drive it around the block and the filter is again full of air, and the car is running like $hit.
Every thread I've read seems to say; primer pump air in=leak out, but I have no fuel leaks, all the fuel lines look good and the suspect ones have been changed. Should I change out the whole housing, the pump only, or am I getting ahead of myself?
Car will idle ruff for a while once I've primed it. which leads me to think the pump housing is working, but I think when I rev it up it's drawing in air through the primer pump and when it idles down that air runs back up to the primary filter. Is this possible?
1983 300D
Thanks guys

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1980 240D(the first, 4spd)
1983 300D(WVO experiment) gave to my brother
1987 300D(sold with 360k+ miles on original #14 head)
1999 E300D 225k miles and counting