The illustration along the top and at the bottom left show the entire fuel and return line routing.
If your electric fuel pump is pushing fuel into your mechanical fuel pump, and the mechanical fuel pump does not have a return line port, then change your mechanical fuel pump to the correct model with the return port. Then connect your return line to the pump and be sure it's connected at the tank.
Venting fuel vapors under the hood is not a good idea. They are highly explosive.
What do you mean when you say:
Quote:
The carb has a fuel line running to one of the headers, which may be a second vapor return.
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And check your fuel cap, if it does not say "vented" then you need to be certain that your car has a tank vent, a small hook shaped tube at the top of the tank. Even if it does, it may be clogged; switch to a vented gas cap and see if the tank pressure drops. Or, after the car has been running for a while, walk back and loosen the gas cap and see if there is any pressure or suction in the tank. There should not be any.
You will find that the shop manuals do not depict every combination built. Air conditioned cars frequently have the fuel pump return line when none is shown in the auto parts store lists, same with fuel tank sending units.
Most common fuel gauge problems are caused by wiring. Either corrosion on the sending unit terminal, a cut or scraped wire where it passes from the trunk to under the car, or along the wire under the car to the sending unit. Problems at the gauge end are usually in combination with other electrical issues and are often caused by poor grounding of the instrument cluster.
Vikki 1969 Goldenrod Yellow / black 400 convertible numbers matching
