engine dies - seems like fuel starved - now fine again?

[Sea++]

Engine shut down, seems to be fuel-related. 2005 SeaRay 320 DA w/ vdrive 350 MPIs

Yesterday, starboard engine died suddenly while under power. We had been at anchor for a couple hrs, then headed home, engines running about 45 minutes, only short bursts under power, mostly slow speed through channels. Restarts failed, engine tried to go, but acted exactly like it was not getting fuel. It it would start, it would only stay running a few seconds, then die again, and any attempt to throttle up caused immediate stop. I tried several more times while limping home on the one engine, hoping I would get it going again. But no luck.

So today, marina was able to fire it right up, no issues at all, no codes (I have the smartcraft system). They ran it for 1/2 hr under mild load (I suspect in gear above idle while tied to slip). They could find nothing. They checked the obvious burned-out problems like fuel pump, no heat damage or other issues evident. They could only guess that something temporarily clogged the fuel tank vent hose.

Any other ideas? I hate knowing that this issue is not solved and will just appear when again...

 

[paulswagelock]

That was the first symptom I had when my cool fuel module died.

 

[Sea++]

So nothing really died, not permanently anyway. Boat fine today according to mechanic. So, when it happens next time (because it will happen again I'm sure), what are some things I can look for to narrow down whats going on. I'll open the engine bay up, but what to look for?

 

[scoflaw]

Test fuel pressure at the rail. Code scanner won't pick this up. Pull the FPR off the CF3, easy job, see if it's loaded up with paint chips

 

[Left Coast Guy]

Are you running fuel Additives? To much additive is not good New fuel runs much leaner now days so when you add more to tank motor builds more heat.

ECM could be overheating

 

[CliffA]

don't assume the issue is fuel starvation......ignition problems can cause the same symptoms.....next time this happens use a spark tester on one of the spark plugs to verify if spark is getting to the plugs while the engine is being cranked.....determining if the root cause is fuel or ignition related should be done before any types of repairs......if not you will likely just waste time and money throwing new parts at the issue until eventually you solve it....

cliff

 

[370Dancer]

hot day? Sounds like vapor lock to me. Merc solves it by masking it with low pressure secondary fuel pumps between the tank and fuel water separator. Other current posts about this.

 

[scoflaw]

hot day? Sounds like vapor lock to me. Merc solves it by masking it with low pressure secondary fuel pumps between the tank and fuel water separator. Other current posts about this.

Dying suddenly while under power doesn't sound like vapor lock. That Merc scanner is real good at finding ignition related problems with that 555 system. On the fuel side it's damn near useless.

 

[Vince_nj1]

Unplug the fuel pump relays and look to see if there is any damage. There are 2 on the top of each motor. http://clubsearay.com/showthread.ph...ged-How-do-I-fix-this-See-Pic?highlight=Relay

You can buy them from Ballenger Motor sports

CONN-33555

GM Delphi / Packard - SPDT Relay, 30AMP, 12 volt with skirt for sealing MP 280

$9.99

 

[Sea++]

Update - fixed (I hope anyway). I finally got down to the boat and pulled the relays. Sure enough one pin looked corroded and slightly brown where it enters the relay housing. I also checked the 3 spade fuses, no problems there. A simple relay swap with the good engine and the fuel pump energized when I switched on the ignition and the engine started right up! I was able to purchase a relay and things seem to be back to normal. I brought things up to temperature, no issues so far. I have a good spare relay in the boat now also.

Thanks all for the suggestions.

 

[velooce]

When was the last time the water separator filter was changed?

 

[Sea++]

Unfortunately I do not know when the last time the water separator filter was changed. So not a good answer. I've already spoken with the marina mechanic and I am planning to do all fuel-related filters, and a bunch of other preventative maintenance items when the boat is pulled out, probably in the next couple weeks. Then I should have a trouble-free season next year (lets hope!)