When I take a blow gun and blow air into the return line from the pump it seems plugged. Shouldn't air blow through it restriction free ? This is on a 73 gs stage 1 with a stock fuel system.
No chance that during a gas tank swap or something the return and tank vent (to the carbon canister) lines got crossed? The tank vent uses something like a 5/16th hose but in the fitting on the tank it has a restrictor down to a pin sized hole.
I would think so, but not 100% sure as I've never actually checked. I just know the evap one because it looks like an easy line to use for an EFI return line, but there is a restriction in the tank fitter there.
disconnect return line at the tank, then try to blow air thru return line. There should be no restriction in return lines.
