2002 SANTE 5.7 Died and won't Start

I have had this boat about a month. I was on an afternoon cruise about 10 minutes in and there started to be a couple of weird electrical concerns. The stereo shut off completely and I had to turn off the boat and start it back up. This happened twice before the boat died and had not ever happened prior to that day. Another strange electrical wonder is the fuel pump breaker has been tripped every time I leave the boat sitting for over 30 minutes for the week prior to the boat dying. The boat ran perfectly until we made it to our cove (100+ feet deep in clean water) I blipped the throttle to move us out more towards the middle and the engine bogged and started running really rough, at time time I was hearing a loud sucking sound coming from the engine. The engine died and now will not restart. It will crank and occasionally backfire but it will not fire and run.

I have checked cap and rotor installation and condition, and verified spark. Verified lanyard placement. Verified proper functionality of all three relays, checked the three fuses for the fuel pumps and all are in good condition. I hear a fuel pump cycle when I enter the key code but I am unsure if it is the low pressure or the FCC high pressure.

There is extremely low pressure at the fuel rail. I would 8lbs or so at most. This led me to believe that the high pressure fuel pump could be the culprit. I pulled the FCC and removed the high pressure pump. After a bench test I found the pump is putting out about 35PSI. Lower than spec but still much higher than what I am seeing at the fuel rail.

I am confused and boat-less for the last few good weeks of the season. Please help!!

Ok, I will pull it and bench test it tomorrow. What is the STO that you are referring to? I have the excalibur not the GT40, although it seems PCM used similar fuel supply systems for both engines.

I pulled the low pressure fuel pump and bench tested it. It is pumping fine, no issues there. So having ruled out fuel pump failure, what else could it be?

That is very helpful, thank you. I will do this if the replacement of the High Pressure fuel pump doesn't do the trick. I already have the parts all together ready for a tomorrow install.

Ok, I finally had some time to work on my boat. :)

I re-installed the fuel pumps (high and low pressure) today. I cannot get the low pressure to prime. Is there a priming sequence for these? Is this a sign my low pressure is bad even after a successful bench test? Thoughts?

Could be a fuel pump relay?

That's a common thing to go wrong with the GT40s, could be a possibility on an Excal as well.

did they use the same non-gasoline rated tube in the fcc in the excal that they did in the gt-40? you could check that for cracks or leaks...free to check, cheap to replace

Well, I spent another three hours trying to fix this problem... and it ended up being a cap and rotor. it was a last ditch effort, and it worked. The 4 month old cap and rotor failed suddenly. how odd is that?

I am back on the water!

Sometimes it's the little things, glad you found it.

Nice work

No idea. There was very slight evidence of corrosion. I small hint of blue, no pitting or wearing of the nodes. I guess it was enough to arc. It was most likely a failure internally of the cap.