Mechanical Fuel Pump Question

[shark]

Hello Gentlemen, I have a 351W based block and I'm using the Carter mechanical pump. The in line fuel pressure gauge is now reading about 2.5 - 3 pounds. My older gauge was not liquid filled (it also started to have low readings) Several months ago I changed over to a liquid filled gauge and it was reading 4-5 pumps but not recently. I have a new fuel filter on the car.

The question: If the mechanical pump is the culprit, do they fail
completely or do they slowly fail and die giving one fuel pressure
from 5-6.5lbs (new) and then progressively lower readings untl
death.....

Thanks, Mike Sharkey

[Bruce Edwards]

Mike,

If you have any dirt in the system it can hold the valves in the pump open and cause a low reading. Are you sure that you do not have a kink in the feed side of the line or other blockage?

[Cobra20646]

Mike,

From my "for what it's worth" department

Had two liquid filled gauges in my car. Both failed to read accurately after a month or so of use. When new, they would read 6 to 7 pounds, but when they failed they would indicate anything from zero to something short of 7 pounds.

Upgraded to an AutoMeter #2172 and have not had another problem in over two years.

Standard disclaimer..... your mileage may vary

- Jim -

[shark]

Thanks guys, I HAD two fuel filters, one just off the gas tank and fitted with a 3 dollar special unit. I recently (a month ago) fitted a Alum. JAZ unit just afer the fuel pump. Well.. I removed the JAZ unit and my pressure now reads 7.5 to 8 lbs. (engine cold). I've gotton some feedback that the liquid gauges will sometimes read normal with a cold engine and engine compartment but will take a nosedive after the engine gets hot. It's rained some much here I haven't checked the gauge when hot yet. We'll see.

Thanks, Mike