Twin 2004 115 both wont start

[Queequeg2]

Twin 115s were running great. Started right up and ran smooth across RPM range. Last time out the Starboard engine started stalling when shifting quickly into neutral. I adjusted the shift sensor and cleaned up some wiring. Then the Starboard engine started but would stall if I tried to shift into gear. Slow degradation until it wouldn't start at all. The Port side still fired right up (at first). Then the Port side started degrading until neither would start. What I've tried so far:

• Disconnect white wires on lanyard. Tested the Lanyard
• Charged both batteries and cleaned the terminals
• Tested the shift sensors (they check out when running YDS as well)
• Ran diagnostics (everything came back okay). Interestingly, when I run the spark test I get a weak spark on every plug. When I crank the engine with a tester I get nothing. I assume this is because the engines are not turning over when using the YDS.
• Tried disconnecting the main harness to attempt isolating the engine. Pulled the plugs and jumped the Red / Yellow. Used the brown to red to crank. Still no spark.

Day 2. I found a thin ground wire disconnected on the Port side. It was with the wiring harness with the Pink, Pink/Black, Pink/White wires, Best I can tell the Pink is the trim sensor (which was disconnected). The Pink/White appears to go to the Oil Pressure Switch. Pink/Black runs into ECM but I don’t know what it does or where it originates. It’s either a Green/Red or Green/White running up to the helm someplace. When I reconnected the black wire, the Port engine fired right up again. Few more tries it slowly degraded again.

I’m stumped, but somehow thinking its related to the Pink/Black wire getting some sort of signal. Any thoughts what this could be?

[Queequeg2]

Further investigation. Looks like Pink/Black are the return for heat sensor. I don't see how that would prevent starting.

I suppose I'll get a peak voltage tester and start looking at individual components. Just struggling with the idea that two outboards with the same fail mode aren't sharing some common denominator.

[99yam40]

you may get some kind of response If you post the complete ID of the motor.
I have no idea if it is a 2 or 4 stroke

[Queequeg2]

Thanks for the feedback. They are F115TXRD 4 strokes. Fuel injected. Are there other features that could be relevant?
I have user and service manuals as well as YDS V1.33. I also have the wiring diagrams for the boat. There's a lot to digest and I'm coming up the learning curve. Or at least trying to.

[boscoe99]

The only part that is common between the two motors is the control box and start switches.

I would start by disconnecting both ten pin harnesses at the motor. Then, on the motor side, jumper red to yellow to simulate the key being turned on. Then momentarily jumper red to brown to crank and start the motor. See if the motors crank, start and run.

Jumper black to white to stop the motor.

[Queequeg2]

Tried that one engine at a time previously. Just went out to try disconnect both at once. The Starboard engine turns over but wouldn't start. The Port engine fired right up for about 10seconds then stalled. Subsequent attempts got a few pops, then nothing. I've been chasing ignition. Could it be fuel related? I checked both filters they are clean & full, water floats are on the bottom. Bulbs are hard. When I connect the red & yellow I can hear the pumps engage (rapid ticking sound). Sound stops after a few seconds but resumes if I start cranking the engine.

[boscoe99]

The only thing that I can think of common to both motors is fuel. And air.

[Queequeg2]

Well I've narrowed it down to fuel. The gas looked yellow, so I hooked up an external tank directly to the low pressure pump. Drained fuel out of the separator. Tried cranking but nothing. Then pulled all four plugs. Used a little spray bottle to squirt gas into each cylinder. Replaced plugs and turned the key. 2 whole seconds of runt time. At least I know it's not electrical. Now I need to understand why and how it's both engines at same time. If it is bad gas:

1. How did that happen. I Used the boat just a week before. Stopped on the way home and added about 20gal of new gas on top of 30 or so that was already in tank.
2. Why doesn't it run on the external tank. Could bad gas still be up in the separator / injectors. If so, how do I get it out.

It starts to make sense though. First the starboard engine acts up, because it's the first one I started running on muffs. Then the Port engine runs, because it has the old fuel in the lines, but degrades after a few minutes.

[boscoe99]

It takes a certain amount of gasoline to work its way to the injectors. You need to purge and reprime the complete system. Using know good gasoline.
n
You could have gotten a load of bad gasoline. It is known to happen.

[Queequeg2]

Thanks for all the feedback. If/when I get this figured out I will definitely post so others might benefit.

"You need to purge and reprime the complete system" How do I do this?

1st - I'm only working the port engine. Assuming whatever is wrong is consistent with starboard side.

I disconnect the injector and cooler rails and drained them. Then pumped the ball until clear fuel came from the external tank through the separator and out of the hoses. Hooked it all up and tried again. That didn't work. This time when I disconnected the fuel lines from the injector and cooler rails there was no fuel in them. Now when I pump the ball (it's hard) I'm not getting any flow out of the separator into the rails. I checked line going into the separator and plenty of fuel there. Also nothing coming out when I open the drain screw. Does it have to be bled somehow?

I also checked the high pressure pump and it gets voltage when I turn on the key for about 1-2seconds. When I activate it I hear a click, but I didn't hear it running. Tried bypassing the blue to ground to see if that was it. Still only a click, don't hear anything running. I assume I should hear some sort of a hum. Hard to believe 2 high pressure pumps fail at the same time.

[99yam40]

Thanks for all the feedback. If/when I get this figured out I will definitely post so others might benefit.

"You need to purge and reprime the complete system" How do I do this?

1st - I'm only working the port engine. Assuming whatever is wrong is consistent with starboard side.

I disconnect the injector and cooler rails and drained them. Then pumped the ball until clear fuel came from the external tank through the separator and out of the hoses. Hooked it all up and tried again. That didn't work. This time when I disconnected the fuel lines from the injector and cooler rails there was no fuel in them. Now when I pump the ball (it's hard) I'm not getting any flow out of the separator into the rails. I checked line going into the separator and plenty of fuel there. Also nothing coming out when I open the drain screw. Does it have to be bled somehow?

I also checked the high pressure pump and it gets voltage when I turn on the key for about 1-2seconds. When I activate it I hear a click, but I didn't hear it running. Tried bypassing the blue to ground to see if that was it. Still only a click, don't hear anything running. I assume I should hear some sort of a hum. Hard to believe 2 high pressure pumps fail at the same time.

if the filters plugged or had water in VST,,you may have toasted the high pressure pumps.
they need fuel flow to lube and cool the motors and pumps as it runs thru them.

I also understand that the motors should have voltage while the key is on and the ecu controls the negative to turn the pump on and off.
you need to find out what is clicking, maybe the main relay?

[Queequeg2]

Figured it out. Water in the tank. So now I'll share some of my lessons learned for the next person.

Initially, I tried to convince myself it was electrical. Because when I pulled the plugs and cranked the engine there was a really faint spark. I'm used to seeing a strong bright spark. I understand these newer engines don't produce a strong spark when you are turning them over.

Boscoe's comment was spot on. If both engines quit at the same time. Once you've ruled out the lanyard, there are really only two things the engines share. Fuel and air. Pull the injector rails and using a small spray bottle with gas give 1 or 2 squirts in each and then crank. If it fires, you have a fuel issue.

Now for the water part. I didn't think it was water because the small floats in the filters were sitting flat on the bottom. So I again tried to convince myself of the highly unlikely failure of something in both engines at the same time. Lesson learned, don't trust those floats and stop trying to convince yourself of highly unlikely things. I disconnect the fuel line to the low pressure pump. Put it into a clear plastic cup and squeezed the ball a few times. With about 5onces in it I set and down and watched. In less than a minute it separated to about 1/2 fuel 1/2 water.

Unfortunately, after cleaning it all out, there's no pressure on the rails. I'm assuming the high pressure pumps didn't like the water and have now failed. I'll have to remove the intake to get at them and replace the pumps, screens, filters...

The only saving grace. The machinic was busy and couldn't come for a few weeks. So now I don't have to pay him to tell me water doesn't burn well in your outboards.

[99yam40]

Figured it out. Water in the tank. So now I'll share some of my lessons learned for the next person.

Initially, I tried to convince myself it was electrical. Because when I pulled the plugs and cranked the engine there was a really faint spark. I'm used to seeing a strong bright spark. I understand these newer engines don't produce a strong spark when you are turning them over.

Boscoe's comment was spot on. If both engines quit at the same time. Once you've ruled out the lanyard, there are really only two things the engines share. Fuel and air. Pull the injector rails and using a small spray bottle with gas give 1 or 2 squirts in each and then crank. If it fires, you have a fuel issue.

Now for the water part. I didn't think it was water because the small floats in the filters were sitting flat on the bottom. So I again tried to convince myself of the highly unlikely failure of something in both engines at the same time. Lesson learned, don't trust those floats and stop trying to convince yourself of highly unlikely things. I disconnect the fuel line to the low pressure pump. Put it into a clear plastic cup and squeezed the ball a few times. With about 5onces in it I set and down and watched. In less than a minute it separated to about 1/2 fuel 1/2 water.

Unfortunately, after cleaning it all out, there's no pressure on the rails. I'm assuming the high pressure pumps didn't like the water and have now failed. I'll have to remove the intake to get at them and replace the pumps, screens, filters...

The only saving grace. The machinic was busy and couldn't come for a few weeks. So now I don't have to pay him to tell me water doesn't burn well in your outboards.

you still need to clean all of the water out of the tank, not just some of it.
have you figured out how you are going to do that yet?

[Queequeg2]

Yes, or at least I have a plan.

I have a small 12v pump with a long 3/8 copper pipe and several feet of tube. 30gal plastic tank to siphon into. I'll pull the sender out of the top of the tank and feed it down to the bottom. Keep pumping until I see clean gas or empty the tank. I figure if I let the fuel separate for a while, I can pump the water off the bottom and use the gas for something else (old lawn mower). Or if it looks bad I'll find a place to get rid of it. Already pulled the two separator filters. Once I have the tank cleaned, I'll use the balls to pump out anything remaining in the lines.

[DennisG01]

Make sure your pump is rated for gasoline!!!!

Cut the bottom of the copper pipe at a slight angle.