Engine sputters & dies while flushing

[alexvelarde]

My 2014 Mercruiser 5.0 L MPI 260 HP sputters & dies after 5 minutes of flushing... It ran yesterday and today on the water perfect. I have noticed this the last 2 times I have flushed it. Any ideas?

 

[alldodge]

Need more info on how your setup. How are you flushing, using muffs or the built in flush connection?
What is your engine serial number?
Does it restart after it dies?

 

[alexvelarde]

It's a 2013, not a 2014 (sorry)
Engine Serial Number: 2A047298
I'm using the dual engine flusher (muffs).
It starts briefly and then shuts off as if it's not getting fuel

 

[Pete104]

Is the front of the boat high enough for fuel to be at the back of the fuel tank? Might be running out of gas.

 

[alldodge]

Does it restart after it dies?

It starts briefly and then shuts off as if it's not getting fuel

Being this new I'm going to need Fun Times or maybe muc to clarify some issues. It ran fine with no issue with normal operation. It was only when it was being flushed on muffs that it would die and then just start briefly and then dies. So there is no issue any other time.

The issue we run into is the motor is so new that Merc has changed things which most have limited knowledge, including my self. My first thought is smartcraft and if the PCM is seeing something like low water pressure at the sensor and therefore shutting down the motor. The water pressure sensor is mounted on the power steering cooler behind the motor (p/n 881879010)

 

[Pete104]

Being this new I'm going to need Fun Times or maybe muc to clarify some issues. It ran fine with no issue with normal operation. It was only when it was being flushed on muffs that it would die and then just start briefly and then dies. So there is no issue any other time.

The issue we run into is the motor is so new that Merc has changed things which most have limited knowledge, including my self. My first thought is smartcraft and if the PCM is seeing something like low water pressure at the sensor and therefore shutting down the motor. The water pressure sensor is mounted on the power steering cooler behind the motor (p/n 881879010)

Good point but low water pressure would set a fault code & possibly go into guardian.

 

[Fun Times]

Is the front of the boat high enough for fuel to be at the back of the fuel tank? Might be running out of gas.

Good thought Pete.:thumb:

If not ^ then here's some additional thoughts just to add to a possible list of many.
What RPM are you running the engine at while on the muffs? Should be 1300 rpm.

When it dies, pull the fuel filter to see how much fuel is inside....You may have to buy a EFI fuel pressure tester gauge to see if it's losing fuel pressure.

Since it's not really starting after shutting itself down, you may want to pull the spark plugs to ensure no water is getting down into the cylinders.

Or maybe being that you have an Alpha One drive, the shift cable isn't 100% adjusted right and possibly the shift interrupter switch is becoming activated but not affected by being under load in the lake water.

How many hours are on the boat?
Is the boat new to you?
Do you flush often for the same period of time in the same location as normal?
Fuel tank level lower then normal?

I'm using the dual engine flusher (muffs).

When I read Dual flush I was thinking Bravo stern drive which some have a low and side water pickup...But you have an Alpha drive. Have a photo of the muffs you are using for clarity ?

 

[Pete104]

I was going ask for clarification on the "muff" he's using as well. Not that it's an issue. The term "dual" kinda threw me.

 

[alexvelarde]

No Title

I think I figured it out... I used to run the engine on neutral without Salt Away (pic below) and it was fine. Recently, I started using Salt Away with its attachment and the engine sputtered and died while flushing.
This time when I flushed the engine without the Salt Away and kept the RPMs at about 900, it seemed to work fine. I ran it for 11 minutes with no issues.
Then, I connected the Salt Away attachment and I noticed the temperature went up pretty quickly. Maybe this had something to do with it or not... I don't know, but it seemed like it was not getting enough water. After I removed the Salt Away attachment, the temperature went back down to normal and everything was fine. Any thoughts?

Btw, here's a pic of the muffs.

 

[alldodge]

Lack of water supply would do it, your muffs are the same as I use