2004 Monsoon 340 won’t stay running

[04wake]

Hello all, I have a 2004 Monsoon 340 in a Wakesetter LSV. The engine will not stay running more than 1 minute at idle or at any given throttle.

Boat worked fine. Put it on trailer for 3 weeks and first run lasted 10 minutes before shutting off randomly while driving the boat. Boat would fire right back up but only for 30 seconds or so. 

Back on the trailer, the first start of the day fires right up. Will idle for 1 minute or so and the turns off as if someone cut the key  

Second start takes cranking for 2-4 seconds and then fires up every time. Stays running for 30 seconds to 1 minute the. Does it again. 

Gauges don’t lose power during a shut off.

Replaced fuel filter and filter in bottom of fuel pump.

checked gas lines, all normal. 

Put outside gas tank with newer gas on at fuel pump to isolate a potential fuel tank or supply line issue.  Same process happens as described above. 

Fuel pressure is still high at the rail.

Trying to figure out what is cutting out. I’m assuming something electrical. Maybe the ecm is killing spark but I have run out of ideas.  

I’m trying to get around $125/hr work fees at the shop, so any ideas I can take a look at would be great.

Thanks for any suggestion. I just can’t understand why it will let me immediately restart the engine every time. It just won’t stay on. 

Edited June 30, 2019 by 04wake
Typo’s

[justgary]

11 hours ago, 04wake said:

Hello all, I have a 2004 Monsoon 340 in a Wakesetter LSV. The engine will not stay running more than 1 minute at idle or at any given throttle.

Boat worked fine. Put it on trailer for 3 weeks and first run lasted 10 minutes before shutting off randomly while driving the boat. Boat would fire right back up but only for 30 seconds or so. 

Back on the trailer, the first start of the day fires right up. Will idle for 1 minute or so and the turns off as if someone cut the key  

Second start takes cranking for 2-4 seconds and then fires up every time. Stays running for 30 seconds to 1 minute the. Does it again. 

Gauges don’t lose power during a shut off.

Replaced fuel filter and filter in bottom of fuel pump.

checked gas lines, all normal. 

Put outside gas tank with newer gas on at fuel pump to isolate a potential fuel tank or supply line issue.  Same process happens as described above. 

Fuel pressure is still high at the rail.

Trying to figure out what is cutting out. I’m assuming something electrical. Maybe the ecm is killing spark but I have run out of ideas.  

I’m trying to get around $125/hr work fees at the shop, so any ideas I can take a look at would be great.

Thanks for any suggestion. I just can’t understand why it will let me immediately restart the engine every time. It just won’t stay on. 

First, bypass the kill switch.  Those things were added by lawyers who know nothing about making engines run, and are known to get intermittent.

Next, how did you test the fuel pressure?  It has to be ~42 PSI at all times (idle, accelerating, wide open throttle, etc).  It is possible you have a spark issue, but make absolutely sure that you have the correct fuel pressure before you begin diagnosing spark.

Next, check the connection to the oil pressure sender (the ECM one, not the dash one).  The engine has no appreciation for thinking it is out of oil, and will attempt to save itself.

If still no joy after picking the low-hanging fruit, refer to (@tvano) Ted's Excellent no-start diagnosis procedure posted as a sticky near the top of the troubleshooting forum.

[ahopkins22LSV]

Here is the no start trouble shooting guide @justgary mentioned. 

 

[blk93jeepzj]

Can check and swap relays too.  The 3 under/behind the middle seat have caused me issues in the past with an intermittent run/don't run.     

[04wake]

Thanks. I switched out the oil pressure switch. Ran this time for 15 minutes before it randomly shut off again. Then went back to its run for 30 secs to 1 minute before turning off. 

Interesting note is that if it is running and I turn it off with the key. It fires on the first crank on the next start up. If I let the engine die on its own. When I go to crank it, it takes 2-4 seconds before firing up. Almost like it ran out of gas the time before. 

 

[justgary]

And the fuel pressure when it died was?...

[04wake]

I know this is reviving an old thread, however I believe i found the issue.

First I replaced the fuel line as it was the original and I removed the filter the goes in the bottom of the fuel pump.  This filter wasn't dirty  but it did squish easily making me thing it might be collapsing and causing a gas flow issue.  

After replacement/removal the boat runs great now is a trial so i do not know if it was the lines collapsing on the inside or the small filter however i will replace the filter anyways. 

Anyone have any experience locating one of the small filters that fit in the bottom intake of the fuel pump? Not having the best of luck.

Thanks

[kylesullens]

On 1/31/2020 at 7:17 AM, 04wake said:

I know this is reviving an old thread, however I believe i found the issue.

First I replaced the fuel line as it was the original and I removed the filter the goes in the bottom of the fuel pump.  This filter wasn't dirty  but it did squish easily making me thing it might be collapsing and causing a gas flow issue.  

After replacement/removal the boat runs great now is a trial so i do not know if it was the lines collapsing on the inside or the small filter however i will replace the filter anyways. 

Anyone have any experience locating one of the small filters that fit in the bottom intake of the fuel pump? Not having the best of luck.

Thanks

can you share a pic of the filter in the bottom of the fuel pump? I have an inline filter but was not aware of a filter on the pump.

I am not experiencing any issues but I like to get ahead of trouble when possible. thanks 

[04wake]

Sorry I have been away.  I will try to find a picture of the filter and send it to you.

[Mauro]

I am interested in the sort of noise the engine did to you. I am experiencing something similar. Engine worked fine then died. Tried turning on and it worked a few seconds. What I associated at first due to the slow start and rough engine( rough because it sounded like a scratching when turning) was the battery running low but I tried different batteries and still no.

I have not been able to retry and film the behaviour as I broke my foot that same day it started misbehaving😅

And recovering.