5.0GL-H have fuel at carb, but won't start when hot out.

[JJ Schnell]

Posted a thread a week or two ago about boat dying on the water and unable to restart. Can't figure out how to edit or update my posts so figured I would start a new thread with an update.

Engine does not want to start the last 2 times we took it out once it gets hot outside. Started fine in the morning when we headed out but even after we had drifted for a couple hours without it running it did not want to restart, about 95 outside right now, was about 105 the other day.

Checked and was getting fuel to the carb when I went WOT with engine off. Finally got it to start today after 4 or 5 attempts today, never did get it started the other day and had to be towed. Had to crank it for a good 9-10 seconds before it fired up. Don't think, although not 100% sure, it's vapor lock as when it happened the other day I cooled off the pump and fuel lines with water and tried starting for almost 2 hours off and on and still wouldn't fire.

Engine only has 240hrs on it and the boat is a 2008 so not terribly old. Fuel is non-ethanol 91 octane. Dual batteries, tried to start with each and then both with same results.

I'm kinda leaning toward fuel pump going bad or possibly an ignition issue?

 

[alldodge]

Your unable to edit a thread after so many hours. To give others insight to previous comments
https://forums.iboats.com/forum/eng...tdrives/10910139-5-0gl-cut-out-now-wont-start

With the GL being a carb motor, there should be no vapor lock issue. If carb did dry out, then it would only take a few cranks for the bowl to be refilled by the pump

If there is no fuel in the carb then there is a electrical issue which keeps the pump shut down. If the pump is shut down this does not relieve the issue that maybe the carb is leaking fuel and therefore has none available when trying to restart

My guess is there is no spark and this should be investigated. The below is a GL-E but does show a relay which powers the fuel pump. Note there are 2 diodes. One is used during the starting cycle (motor cranking) and the other is once motor starts

See if you have voltage going to the pump when the motor is cranking

 

[JJ Schnell]

Thank you, wasn't sure as to the editing as any other forums I'm on allow it until it's archived.

It's getting plenty of fuel sprayed in the carb when the throttle is moved WOT before trying to start so I know the carb isn't dry.

 

[alldodge]

Sounds good, so its an electrical issue
Does it have the EST distributor or another?

 

[JJ Schnell]

Looks like the EST but how to tell for sure?

Just weird how it can start so good in the morning then not want to at all a few hours later.

 

[JJ Schnell]

Just went out and tested wires going into the fuel pump when I tried to start it and they registered 12volts and it fired right up! Getting so frustrated with not knowing if it's going to start or not.

On a side note and possibly another issue, there is a rattle coming from the outboard drive when at idle, goes away as soon as it gets put in gear?