I have a 455 with a holley 650 and holley electronic fuel pump.  I took the boat out a few weekends ago and ran it at 4500 rpm  for 10-15 min and it stalled out and died, the fuel pressure went from 9lbs (when running @4500) down to .5lbs. I'm going to take the boat out again this weekend and have the fuel pressure set to 5 lbs instead of 9 lbs and see if that makes a difference.  Also after it stalled out I started it back up and ran it at 3500 rpm with no loss of fuel pressure and no stalling out.  Any help would be appreciated

Sent from my SAMSUNG-SM-G900A using SoCal Jet Boats mobile app

Another question was should I swap the holley electronic fuel pump out for a manual one?

Sent from my SAMSUNG-SM-G900A using SoCal Jet Boats mobile app

Mechanical is the way to go... 9#'s of pressure and it ran?

A few simple things come to mind.

Fuel tanks clean? Could have restricted pick up tubes.

Tanks vented properly? Crack a fuel cap and see if it makes a sucking sound after the pressure falls.

Collapsing fuel hoses? How old is the hose?

If I was to make a wager, I would say the fuel pump is working great and the problem is fuel related.

Fuel pressure should be 6psi from idle to balls to the walls.

Good hunting.

GT

Sent from my SM-G900V using SoCal Jet Boats mobile app

Thanks for the reply,  ya it ran with 9lbs,  I had it set at 9.5 on idle then when I was running it it would drop to 9 them after awhile drop to .5 amd stall out. Tanks could be dirty inside but I do have all new line from tank to carb and from regulator to carb is steel braided.  The tank is vented out the side of the boat and I've seen fuel splash out if it so I don't think it's clogged up.  I'd take the fuel cap off but it's stuck on there pretty tight.

Sent from my SAMSUNG-SM-G900A using SoCal Jet Boats mobile app

I guess what I meant by the fuel cap is to open it and see if the tank is in a negative.

Do you have a fuel selector valve? And what filter?

GT

Sent from my SM-G900V using SoCal Jet Boats mobile app

Fuel selector valve? Like switching between tanks?

Sent from my LG-K330 using SoCal Jet Boats mobile app

Yeah, those things are prone to having the o-rings coming apart plugging them up.

I use a 3/8" brass tee and two full port ball valves. Just make sure they are rated properly. Look for "WOG" on the handles.

GT

Sent from my SM-G900V using SoCal Jet Boats mobile app

Stupid question, I have a pull out switch for my gas tanks. Don't know which tank goes to either pulling out or pushing in. Lol. Is there a default direction they go?

Sent from my LG-K330 using SoCal Jet Boats mobile app

Well, yes, and no.

Most of 'em are off of 70's GM and Ford pickups.

And most likely its just an on/off switch. My Chevy dually fuel switch- off-right side, on-left side.

My daycruiser is the same way. Just a 3 way switch.

Dan'l

Fill one of the tanks with water. When you switch the tanks and the engine does, BAM, Bob's your uncle...



Lmao

GT

Sent from my SM-G900V using SoCal Jet Boats mobile app

Lol! With my luck it would be on the tank with the fuel in it when it goes BAM!

Sent from my LG-K330 using SoCal Jet Boats mobile app

The fuel filter is new from oriellys don't know the brand though.  I have 2 filter on it, the one from oriellys a foot before the regulator and an edelbrock filter after the regulator.  And I don't have a selector valve

Sent from my SAMSUNG-SM-G900A using SoCal Jet Boats mobile app