Packard Forum Index » V-8 (1955-56)

When I finally made it home yesterday I should have (always 20-20 hindsite) raised the hood and checked the bowl filter at the carburetor inlet to verify it was boiling. I am going to remove the extra filter screwed into the electric pump since it is the most restrictive and I have the clear filter ahead of it and the original bowl filter at the carb. inlet. With clean gas tank and lines, I don't need all that filtration anymore.
Also I have seen it recommended numerous times and have done that in my Hudsons of adding ~ 8 oz. of Marvel Mystery Oil to the gas tank to help alleviate the problem. Some say a little diesuel fuel will help, but I'll just go with the MMO.

The line between the pump and the carburetor (with the glass filter) is the least-likey place to have vapor lock because the fuel is alternately under the pressure of the pump (3-5 psi) which raises the boiling point.

Removing the filters may very well help, and the MMO may also. I'd also suggest you remove the outlet line at the tank and the inlet to the pump, plug at one end and attach to a vacuum pump to see if it will hold a vacuum - the smallest of air leaks, even those so small they don't leak gasoline, can give similar problems.