fuel pump help

hoggyrubber

i have been wrestling and wrestling trying to get my fuel pump to work and i am really out of ideas and thought you guys might help. i got my orig d/a fuel pump rebuilt for the 52 308 i have. i installed it and removed the electric one i had been running. i could not get it to pump any gas. engine would run when i filled fuel bowl but as soon as it was out, die.
the rebuilder graciously let me return it for a replacement. i installed the second one same deal. i even bought 6' of new fuel line and a new filter to take that out of the equation. i put one end in a gas can below level and it wouldn't pump any out. i am running the original gasket that is about .285" thick. i also changed out the original fittings on the carb to brass pipe to barb for new rubber gas line. i checked the lobe on the cam and it feels fine no noticable wear.
i hooked up the pump to a vacumn gauge and it wouldn't pull 1" of vacumn when operated by hand on either fuel or wiper incoming port. i checked with a fuel pressure gauge and no noticable pressure on the outgoing side. i didn't hook this up with airtight fittings, i just used a beveled rubber end like on a compression teaster. i have no idea how much vacumn or pressure these should show when just operated by hand, prob not much.
anyone have any ideas what it might be? i don't see how the new fittings could be blocking flow. i don't know a way of checking to see if the cam is actually working the arm on pump once it's attached. like maybe the distance is off with the gasket. i was careful to put pump on with arm below cam and used lucas assembly lube on cam lobe. the rebuilder checked out first pump i sent back and said it was all in working order. anyone have any ideas or suggestions, i don't want to go back to electronic pump after i removed it?

hoggyrubber

thank you both for the info. i was thinking it was something like that. looks like my gasket is too thin since it is just a little over 1/4". i guess i can make a gasket to add to the thickness? i am going to charge the battery and give it another try. i'm not that concerned about the wiper part, i don't drive that much in the rain. the fuel electric pump i9 had would occasionally cause it to flood when starting and seem to starve a bit at higher rpms. however it said to locate close to tank and i had mine in engine bay, since it was a temperary(hopefully) setup. thank you both again. stacy k

hoggyrubber

well i thought i would come back and let you guys know what i tried. however it still isn't working! i made up a gasket that was 3/16" to get it to the total 7/16 thickness. i also marked on the arm pad with a sharpie so i could tell where it hit. i was careful again to get it under the cam and after cranking the engine nothing again! when i removed it it was hitting right in the center of the pad so at least i know it was under and right where it should be.
i also tried blowing a little compressed air thru it. it would not blow any when i tried thru the inlet side, but it would blow when tried i tried thru the outlet side. also i tried the vacumn gauge/pump again. when i pumped on the vacumn gage itself on the inlet side nothing. when i pump with it on the outlet side it would pump up vacumn and when i would work the arm on my fuel pump, the vacumn would go down.
anyone have a clue what this means? it seems to rule out distance of gasket, new fittings blocking flow, the pump itself seems to be doing something so it prob works fine, and the gas can with new hose rules out the tank. anyone have any other ideas?

brumac

Hoggy, I seem to remember that there are one way valves in the inlet and maybe the outlet too (it's been about 30 years since I had one apart) . Sounds to me that they may be installed backwards. Maybe you could hook the outlet side to the tank and the inlet to the carb and see if that works.
good luck, Bruce

[Deleted User]

I tend to agree with Bruce on the flow direction . The check valves would hold presure in the line to the carb. And you blew in that line and air passed thru- this indicates to me valves are not holding or in backwards.
Roger

lostmind

Sounds like the cover needs to be rotated 180 degrees.

hoggyrubber

just wanted to let everyone know i got this fuel pump issue resolved and i wanted to say a big THANK YOU everyone for their help. got to go for a ride today and i got around to adjusting the valves for the first time since i got the engine together and that was just a cold adjustment. the engine still seems to cut out a little bit at higher rpms. i thought it was the electric fuel pump doing that but it looks like it was something else. oh well, i'm glad to have the mechanical one on anyway.

MikeWA

So how did you get it resolved? Inquiring minds want to know. . .

hoggyrubber

i took out the bottom fuel valves and reorientated them like everyone sugested and how the manual has them. put it back together, and still no go. so i bought another one, fired right up. don't know what the deal was. maybe i didn't get the diafram in exactly correct when i reassembled it. either way, it's running, i learned quite a bit about the pump, and i'm happy.