Fuel Delivery Issue

[edadams]

Fuel delivery issue….I have a ’97 Nautique with the GT40 motor. The other day I was going down the lake at 20 mph and it completely died (sounded like it ran out of fuel. Ever since it has been difficult to start. Prior to the start of the season I replace the Fuel Control Cell (FCC) filer (5 hours ago). Ran great until the other day.
Trouble shooting I have done:
1) Turned the key, but did not start the boat to check the fuel pressure at the rails (38 psi), it does not always hold pressure. Approximately 70% of the time the pressure immediately drops to zero.
2) Cranked the boat with the pressure gage still attached to the rails, after several attempts it finally started. The pressure fluctuated between 35-42 psi at idle. The needle on the pressure gage bounced between 35-42 (not a consistent pressure).
3) Verified that the hose that connects the High Pressure pump to the FCC does not have a crack…no crack.
4) Disconnected the power at the FCC and checked voltage…12 volts as soon as I turn the key to the on position and then slowly drops to zero.
My questions:
1) I know the low pressure pump shuts off after 2 seconds if the boat is not running, does the high pressure pump do the same?
2) Do fuel regulators fail?
Not sure where/what is causing my problem any help would be greatly appreciated.

[SVXTC]

Sounds like you have a bad fuel pump. When they start failing often times its intermittent, sometimes will run fine for weeks on end, but its failing. The lower pressure pump is to keep the FCC full of gas and the HP pump is what is providing pressure to the rails and engine. If you want you to check it could be three other things... make sure your lanyard/safety switch is OK, I believe you have a second fuel filter in line (not positive though) or maybe you have a bad fuel pump relay (could be part number R130011, but double check). My bet is the HP pump though.

[edadams]

Thanks SVXTC,

The lanyard appears to be ok...not really sure what to look for here other than it is still connected.

No second fuel filter (in line)

How do you check the relay? If it is the relay then why would the rail immediately loose pressure in a key on/engine off scenario?

Thanks again.

[SVXTC]

Lanyard... you can bypass them if you need to check some things. Relay... sometimes they will heat up and loose contact or just corrosion etc. Like I said, more than likely its the fuel pump, but a relay is about $15 so cheap to eliminate. I'd just order up a pump and relay and be done with it unless someone else sees something we are missing here.

[edadams]

How do you bypass the lanyard?

There are two relays, which one should I replace?

Thanks

[JayG80]

http://www.planetnautique.com/Correc...e%20Manual.pdf will show you the relays and steps to troubleshoot fuel delivery issues. Including checking the anti-siphon valve, using a stethoscope to listen to injectors to see if they are leaking down. Low Pressure pump is likely your issue. Manual has a test there too. Flow rate and pressure.

Look on the back side of lanyard and pull the 2 wires off and connect them together. If that cures it then butt splice the 2 wire and bypass the switch, if not then re-attach as they were.