95 GT-40 Pro Boss EFI not starting, several tests done already, searched.

[Bwalt302]

I have searched and tinkered with the boat for hours today with no luck. So I come here for help.

I have replaced both the Fuel Pump Relay and the other one beside it (not sure what that is for)
I have checked to make sure no circuit breakers are tripped. There are no blown fuses. Boat does not have a lanyard.

My issue is the boat will not start, it turns over, battery is brand new and kept charged. I have spark, the rotor button on the dist. seems okay. The fuel pumps (high and low) ONLY come on when I jump the STO connector. What does this indicate and where should I look in order to get it to prime when turning the key?

I have fuel going to the rail, and when I press the shredder valve after letting the pumps run for a bit, it squirts out a little bit of fuel (doesn't seem like high pressure, but it is filling up).

Injectors are pulsing, but when I pulled the plugs I did not smell fuel. When I sprayed starter fluid into the throttle body, the boat did fire up and try to run, but wouldn't stay on. This leads me to believe that it is strictly fuel related. I am looking for advice on the next steps to take. Thanks for any help! The boat DOES NOT have an FCC. It is the 1996 PCM Pro Boss GT-40 EFI engine.

[brettmcox]

Any Chance you changed plugs and or wire? Could be Bad or messes up timming?

[Bwalt302]

Plugs and wires are fine, my main concern right now is the fact that I have to manually prime the fuel pumps. As stated it fires up with starting fluid, which tells me plugs and wires / timing are good enough to at least get it to run. I do plan on replacing them later on.

[Bwalt302]

So, I just removed the ground to the STO and jumped the Red and Green wires and the pump came on, could it be a bad ECO, where is this located, again, I don't have a lanyard anywhere... just a regular key.

[2000superdare]

I have had similar issues first time was a diode in the harness (from previous owner attempting to replace starter with battery connected) a few inches from the solenoid under the ecm. Last season I had the same issue due to a bad ground on back of motor where the ground from the fuel pump goes. Id check connections on back of motor first.

[Bwalt302]

Thanks for the info, as far as I know and have checked all grounds and connections are solid. I will look into the diode suggestion. I read something about pins 52 on the ECM (computer) and pins 40 / 60 but the articles I read were un-clear on how to test them.

Do I just check the 52 pin (blue / orange stripe) by sticking the ground from the volt meter in it and then a 12 volt source on the positive and if it is grounded its working? Can someone help me out with this, I know the computer got wet but the boat runs with fresh gas and starter fluid by jumping the pumps....

[Bwalt302]

So, I stuck the negative cable on my volt meter into plug 52(blue w/ orange stripe) and the other end on 28 of the fuel pump relay (I think? It was the one that was yellow with a green stripe.). I set the meter to read the lowest OHM setting and when I tested the connection with the key on and off it read 1 - when I hit the two ends of the multimeter together, it reads 0.1 or 0 - so does this mean my pin 52 is not grounding? If so, where do I check to further diagnose?