Power to fuel Pumps GT 40

[MTRBTR]

I just bought a 97 Sport Nautique with the GT 40 Pro Boss.

The boat will just randomly shut down on me. When it runs it runs great. The previous owner just replaced the FCC last year. I replaced the fuel filter just to eliminate that issue. We found that it seems like the power is intermittant to the low pressure fuel pump. Sometimes when you turn the key. The pumps dont come on. Sometimes they do. If they do the boat always starts. Seems to run fine until I idle down and then sometimes it dies and sometimes it doesnt. If it dies usually the pumps dont come back on if you turn the key. If you wait a while and turn the key the pumps will come back on and it will start. I took it to a marine mechanic and they said that the pressure on the fuel rails seemed to be running low but they had not put it under load. They think it might be the high pressure pump which was just replaced. I kind of doubt it. Of course when they checked the power to the fuel pump seemed to be there.....my question is....should there be power to the fuel pumps all the time? I replaced the wires all the way back to the relays and replaced the relays with no change. Summers are short up here in MT....hoping someone has some ideas. I dont know which wires I should check next.

[crobi2]

You might check the integrity of the emergency cutoff switch if you haven't done that. If I understand correctly, it works by cutting out the fuel pumps. Next, you could check the master power switch. Good Luck!

EDIT: If you have some extra relays, you could try replacing them to see if that helps. They are available from White Lake, SkiDim and others.

2nd EDIT: You do need to know if the fuel pressure is low. I wish your mechanic had given you a straight answer there.

3rd EDIT: Just saw that you replaced the relays, sorry.

[DanielC]

My thread on checking fuel pressure.
http://www.planetnautique.com/vb3/sh...=fuel+pressure

[MTRBTR]

Thanks for the ideas, I am going to try to check the fuel pressure tomorrow myself on the water. Where would I find the master power switch?

[DanielC]

The boat originally did not have a master power switch. It just had the push button breakers, to the left of the steering wheel. There are two rows of breakers. The left row should be from the top, "blower", "Ign", "Bilge", "Navigation lights", "Anchor light".

The "Ign" breaker functions as the "master" power switch. None of the other breakers have power applied to them until the "Ign" breaker is pushed. The light by the "Ign" breaker only comes on when it is pushed, AND the key is switched on.

At least that is how the boat was set up when it left the factory in 1997. Somebody else may have changed something.

[MTRBTR]

Yep thats what I have. If I remember right from last time, I have power from there but thats something I will double check tomorrow. Thanks for the input

[MTRBTR]

Ok, So just to close this thread out.....I am a complete idiot. It took 2 weeks and about $200 but I noticed today that it was cutting out when I went over other wakes. Found a loose connection at the battery cable. Glad to have that solved. Thanks guys for taking in interest in my "fuel problem".