Mercruiser 5.0L engine cuts off

[FabienLamour]

I have been having issues with my 2007 Mercruiser 5.0L since the spring. I purchased the boat last fall and it appeared to be running fine when I baught it, but was a bit lazy.

so I replaced:
- engine oil, filter, gear lube
- gas filter, emptied gas tank because I had water in my gas
- sparks, wires, rotor, cap
- idle speed control motor
- impeller

i got the entire cooling system cleaned up.

my engine cuts off randomly with the audible safety beep. More so at higher RPM, lets say over 2000. It idles good and starts just fine. Sometimes i can ryde for 15 minutes without any issues.

i am desprate beause i am over a $1000 in repairs and still have the issue.

what can it be?

thank you for your help and advice.

OW689770 engine serial number
OW895836 Alpha drive serial number

 

[Scott Danforth]

what is your fuel pressure?

you may need to get software like rinda and plug a lap top into it http://www.rinda.com/

 

[tpenfield]

MPI engines are tough to diagnose without the computer software.

Mechanically, about the only thing you can check is the fuel rail pressure.

 

[Searay240sd]

Was it shutting off before you did the tune up? I would double check to make sure all of your plug wires are still connected. I had the same EXACT problem and one of my plugs wires fell off. I would also invest in a fuel pressure gauge to monitor fuel pressure though all rpm ranges.

 

[Searay240sd]

I would also check all of the grounds on the battery and on the engine block. Take the wires off and wire brush everything. I have a tech mate pro and it did not show any codes for a cylinder misfire.

 

[FabienLamour]

Thank you all.

I got the fuel pressure tested by a mechanic and apparently it is perfect, even at high RPM.

When I purchased the boat last year, I took it out for a 1 hour ryde and all was good. It is only after the major tune up and when I found out water in the tank that the random cut off started. I removed the gas tank and emptied it completely.

Could it be a bad spark plug or a bad wire? They are all new, and I got rid of the old ones...I would have to purchase new ones to test it I guess? What about, rotor, cap or wires, could that cause that type of random safety cut off?

 

[Searay240sd]

What plugs did you use? Double check to ensure all the wires are all connected

 

[kulle]

I am having similar, engine just shuts off like a key was turned off...I dont think yours or mine sounds like fuel or it would sputter to a stall. I had loose battery ground, which i dont think was the smoking gun, but i can run the boat longer before it stalls.Does yours start right back up? If it was plugs or wires, i'd expect it to not stall, rather run like crap.

 

[FabienLamour]

My engine only stalls on occasion at low RPM, but the safety beep does not beep when it does. It is key to note that my engine does not stall, it drops by 1000RPM with the safety beep and keeps going until the next beep and RPM drop seconds later. I believe I might have introduced this problem with my major tune up, but unless I purchase another set of sparks, wires, rotor and cap, I cannot tell if this is the culprit.

 

[FabienLamour]

Based on my troubleshooting, i think i introduved the issue with the tuneup.

how can i check the cap and rotor to ensure the replacement parts are ok?

 

[Cerhai]

Let us know what you find, sounds like I have the same problem

 

[Bdaviskar]

If a MPI boat stalls or drops rpms due to a bad spark plug, plug wires, rotor ,cap and or fuel, would it trigger the quick audio SINGLE beep/ alarm mentioned above. If so, how would the ECM know to sound the alarm? Thank you.

 

[Stonefingers]

Did anyone ever find a solution, I have the exact problem and have run out of things to check/replace