So I've installed a fuel pressure gauge in my 74 mav with a 250 and it's reading very low. I'll start the car and the pressure with sit around 5psi then after a few minutes it will drop to around 2psi. I've tried another gauge and same thing. I can feel the pump working and I can see it pull fuel into the prepump filter I have, be it rather slowly in my opinion. Could the pump be slowly dying? It is the original. Also engine starts to sputter a bit once the pressure starts to drop. Any thoughts would be great. Thanks
where does gauge tap fuel line?. . once fuel bowl is full at idle, filter flow slows dramatically but pressure should not. does pressure rise when engine is accelerated? , it should... . . also: "... engine sputters a bit once pressure starts to drop... " - MAYBE drops when carb is simply opening up fuel bowl needle valve or even could be flooding engine, which would drop pressure. . new pump may give same results - then you have a spare . . hav fun
The gauge is right in front of the carb. The pressure doesn't change with revs. I've read that once these gauges get hot the reading will be off which kinda makes some sense. Once I shut the engine off the pressure slowly goes back up then eventually drops to 0 once the engine cools. I'm kinda at a loss with this one.
Jeff has the opposite problem. his new pump would peg his 25 PSI gauge. He took the pump back and got another one that did the same thing.
I am now on pump number 6 with too much pressure...about to be number 7. As long as the store lets me keep returning...I will keep swapping.
