455 fuel pump?

[warpt]

i think that my fuel pumps is bad, i have 9 pounds of pressure at idle but when i get it up on plane and running about 20 seconds i slowly loose pressure. do you think that this would be for sure the fuel pump or maybe a clog filter or fuel line closing itself when sucking? it has a holley pump on it right now, do they sell rebuild kits for them its a mechanical one.

[Boatcop]

Had the same problem with mine.
Check/clean/change fuel filters.
Also check the fuel lines. If they're old (and with a 455, I'd almost bet on it) they may be collapsing and restricting the flow.
I changed out all the fuel lines, and switched to a spin-on marine filter/separator.
No more on-load miss or stalling.

[Rexone]

Also if you have little filter in the front of the carb (QJet) (brass or paper) check it. Even if the brass looking ones "look ok" many times they are not ok...
Personal experience on that one... :(

[FASTRAT]

i think that my fuel pumps is bad, i have 9 pounds of pressure at idle but when i get it up on plane and running about 20 seconds i slowly loose pressure. do you think that this would be for sure the fuel pump or maybe a clog filter or fuel line closing itself when sucking? it has a holley pump on it right now, do they sell rebuild kits for them its a mechanical one.
thats way too much psi at idle...most mech fuel pumps put out 6-8 psi without useing a reg!...anything over that is supposed to have one...my mech pump runs a constant 7psi...fuel filter/filters could also cause part of the prob...i run 2 filters...1 before & 1 after the pump...also ck to see if ur tanks are venting properly...if not...that can cause fuel line collapse...if u chng the lines, dont forget to use USCG approved ones!...most mech pumps that come apart can be re-built...the diaphram can be re-placed...just my .02 cents...Good Luck
fastrat