Shutting off 3 seconds after start and will run if I hold start button - GT40 5.8 EFI

[Rrichr]

I do not have a safety switch as the previous owner by-passed it. When I initially put power to the system the fuel pump engaged and then because I was not ready to use it I pushed the stop key to take it out of run mode. I cam back a half hour later to use it and it would start but would shut down 3 seconds after I started it. I read all the threads I could find about this being a lanyard issue so I even cut the safety switch by-pass wires and made sure when I reconnected they had a clean connection. I swapped the 2 relays on the motor and no change. I checked the 20am fuse at the battery and that is good as well.

Thanks to my buddy I got to ski today anyway I have the GT40 manual but it is telling me to do the Quick Test but that requires that the engine be brought up to temperature and I can't get it there...

[jhersey29]

Toss a fuel pressure gauge on the rail and verify its loss of fuel pressure. Sure sounds like it but best to verify.
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[Rrichr]

I have no pressure… I tried to bypass the computer by completing the ground on the STO connector as well and it is not activating the pumps. The pumps must be working as it will run when I keep my finder on the starter for as long as I want it to run that way.

[Rrichr]

I also replaced relays with no change

[jhersey29]

Keypad issue? Guessing a bit. What about pushing the stop but to a bunch of times I case its stuck. I don't have a keypad boat so just guessing a bit to provide some direction. If your in Denver I have a spare ECM you could try yo see if that is it.
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[Rrichr]

I pulled the connections on the pad and put them back. I have disconnected the battery, then tried again. I am wondering if there is another connection point somewhere for the safety switch that is by-passed?

[Rrichr]

jHersey29,

I thought I have no pressure becuase there is a relief valve on the FCC unit but I must have pressure if I can start it again and with the start button depressed even a little it continues to run.

My thought are switching to electrical after sleeping on it.

I have Breaker Panel part #S6289 under my dash but I really don't know how it works as it looks like it has little rubber caps over each circuit... it could be a darn breaker but I can't see how they operate.

[Treybizttu]

jHersey29,

I thought I have no pressure becuase there is a relief valve on the FCC unit but I must have pressure if I can start it again and with the start button depressed even a little it continues to run.

My thought are switching to electrical after sleeping on it.

I have Breaker Panel part #S6289 under my dash but I really don't know how it works as it looks like it has little rubber caps over each circuit... it could be a darn breaker but I can't see how they operate.

They will be soft if the breaker is okay but firm if it has been tripped is my understanding. Basically a little push button for reset.

[DLafont]

Sounds like the signal from the keypad is at fault, perhaps a loose/broken wire somewhere. The fuel rail has pressure (??), so both pumps seem to be doing their part. I have the same engine in my boat, and ended up changing both pumps to remedy a similar problem this past summer. FCC was a pain to open in boat, easiest to remove it completely then place in vise to unscrew. Keep us posted!

[Rrichr]

When I go back I will have a tester to determine continuity... I want to trace the purple wires that had the safety switch on it.

[Rrichr]

Would the "start run" breaker on the panel be a reason for it to not stay running after starting successfully? Based on its name I would think you could not start at all if it was tripped.

[2000superdare]

If the computer were to go bad none of the other buttons would work on either keypad left or right of steering wheel. I would put good money that your keypad is bad, depending on what model boat you have, the way the keypad lays in the dash water builds up and sneaks its way into the keypad. Sounds like a contact problem inside the keypad which i've encountered before im on my 3rd keypad in 4 years.

[Rrichr]

Thanks 2000superdare,

I will be tracing back from the solenoids and relays and hope I find it before I get to the computer or key pad but don't mind spending the money if it is in fact the part.. its that buying parts I don't need that bugs me.

[Rrichr]

So education is a good thing and I have learned a lot about my boat.... All it was was the breaker in the breaker panel in the kick plate. I put the ignition boot on and cleaned up the wiring a bit near the relays. Went for 2 boat rides