Starts but dies right away, low fuel pressure

[riley456]

Was hoping to get some help for my 2001 SAN gt 40. Had no issues all summer but four days ago was running it pretty hard with alot of people on board. I felt a slight hesitation and then about 30 seconds it died and would not restart. Fast forward 2 days replaced one of the batteries (tested and was bad) and the alternator (tested bad as well). After replacing both, fired up great and thought we were good to go. All gauges read good voltage, oil pressure etc. Took it out and was great for the first minute, got it up to 3700 RPM for about 30 seconds. Then it started to bog down so I shut the motor off to check belt and battery. Both looked great. So tried to restart it and it would not. So after that run, we have changed fuel pump relay, tested batteries (all came back fully charged), bypassed safety switch (did not help), and then we hooked up a fuel pressure gauge at the FCC and got nothing. The current systems are that it starts but dies immediately. Any help is appreciated thank you!

[riley456]

Sorry want to add that we hear the fuel pump priming when we start the ignition.

[gmustangt]

Did you replace the fuel pump?

had a pump fail ( on a car ) recently on me. It would start and run around low rpm fine . Go up in load/rpm it wouldn’t keep
up.
Seeing how you were able to get it going for 30 seconds , the pump wasn’t completely dead

[riley456]

I have not replaced the fuel pump. I actually just pulled the fuel filter (bought the boat this year) and it looked like it hasn't been changed in a very very long time. So just ordered a new one. If that doesn't work, or any of the other cheaper fixes don't don't in the next few days I am thinking I need to buy a low pressure fuel pump. One odd thing was the FCC had barley any gas. I don't think even a super dirty filter would cause zero fuel pressure but I can never be sure.

[charlesml3]

If there was little to no fuel in the FCC canister when you took it off, it's the low-pressure pump. That's all that pump does. It keeps the FCC full at all times.

[riley456]

Alright thank you. Will get that ordered today!

[riley456]

It was the low pressure fuel pump. Thank you! If someone does stumble upon this, when I hit the start I heard a noise but it was actually the high pressure pump that I could now hear because of no fuel. In reality the low pressure wasn't priming at all.

[riley456]

Well apparently I was wrong, although it started right up the garage 3 times, good oil pressure etc, we took it to the ramp and would just crank no start. I checked the FCC and it is now full of fuel. So i can be sure the low pressure fuel was not working and is now working with the replacement. After the no start brought back to garage and still will not start. All 3 batteries are at 12.64 (forgot charger at a friend's house). Is this not enough to start? I would assume it is. Any other suggestions would be welcome. I'm losing summer here!