Re: marks 52 300... continuing where dad left off.

Posted by HH56 On 2013/9/11 20:00:13

If the pump checks OK, while looking inside try to angle so you can get a look at the pickup tube. If the car sat with tank less than half full it is possible pinholes could have developed. Known locations are in the pickup tube at the "U" bend directly above the open end or at the bend where the line exits the tank. If the fuel level is below that point, either could cause the pump to pull air instead of fuel.

If the tank is pristine, any chance it was treated with one of the coating compounds. If those are allowed to dry with the tank flat they have been known to puddle and harden in the pickup area blocking the tube.

If you are checking flow at the carb and going thru the mechanical pump, if car still has the original flex line between pump and steel line those have been known to harden enough so the lining cracks and restricts or completely blocks flow. There should also be a screen affair in the bottom of the mechanical fuel pump. That could be full of rust particles.