Engine starts then cuts off

[DMil26SD]

Need a little help with my 2012 V8 380 -C -B (150hrs). Was at anchor for about 4 hours. Started engine then went to pull anchor and engine died. Tried to restart but engine would not hit. Waited a few minutes engine started but died again. Had to get towed to the Marina. Checked fuel filter/water separator for water in the fuel but found nothing. I did restart the engine in the slip. Ran maybe 5 minutes. When I put it in gear, it died. I can’t get a mechanic for weeks to check diagnostics. I suspect fuel pump or throttle position sensor?

[stifflkd]

Try starting your engine with the engine out of gear and with the throttle above idle RPM's. If it runs fine then it is most likely your Idle Air Control valve (IAC). Pretty easy fix.

[DMil26SD]

I did try that too. It would not start with the throttle in that position. I really suspect the high pressure fuel pump but I have no way to test the pressure on the fuel rail. Still waiting on my turn with a mechanic. Hoping a diagnostic tool will give some direction as to the issue.

[DMil26SD]

I was hoping someone here had a similar problem and could share what the solution is.

[billk2632]

Have you tried to start it after it sat overnight and cooled down? What you describe sounds like vapor lock - definitely if it started after it cooled down. What happens is after running and shutting down with a hot engine, the fuel in the fuel line heats to the point of vaporizing. Fuel pump can't pump vapor, so engine won't start and if it does it will usually stall right out. Once things cool down and the vaporized fuel returns to a liquid, all is well. Never had my VP vapor lock, but both of my SeaRay's with MerCruiser's did occasionally. It can be exasperated by winter blend fuel if you still have any in your tank.

[DMil26SD]

Vapor lock might be the issue but after the stall and tow on Sunday, I went back on Tuesday and the engine started as normal. I let it idle for about 4 minutes and when I put it in gear it died immediately. I was able to restart but within 30 seconds while still out of gear, it died. The engine had warmed up so I suppose it could be vapor lock? I had the hatch open the whole time and the air temp was 84. Boat is in a covered slip.

Let me discuss the fuel. Last October prior to winterizing the engine, I had topped off the tank and put fuel stabilizer in. Last Saturday I had ran enough of the old fuel out that I got my first fill up this year. The tank had about 1/4 left. I put in about 26 gallons. My first thought was that I’d gotten some bad fuel. Maybe contaminated with water. I pulled the fuel filter and found no water at all. The fuel came from one of the marinas on the lake.

[Kate]

"I pulled the fuel filter and found no water at all."

Did you pour the contents into a glass jar, then let it settle?

[DMil26SD]

I didn’t have a glass jar but I put it in plastic water bottle. Yes I let it settle.

[billk2632]

Based on that it starts and stalls after it cooled, you can rule out vapor lock. High pressure fuel pump sounds like a candidate. If you can’t check the fuel pressure, you can at least pull the pressure regulator and check for clogs / paint chips - VP has had issues with paint flaking from inside the fuel pump housing. Symptoms are the fuel pump getting loud and fuel pressure problems. Paint and debris at the pressure regulator are a telltail sign of the problem. Seems to happen more on engines that run ethanol fuel. It a pretty well known issue that to my understanding has not been addressed - VP is still painting the inside of the fuel pump housing.

[bruceb58]

Buy a fuel pressure tester.

[Kate]

"Let me discuss the fuel."

Any ethanol in the old or new fuel? Under certain conditions, it can create gunk, and cause the symptoms you described.

[billk2632]

If you want to diagnose any of this yourself, check out www.mancavemechanic.com, he has done quit a bit of work around the VP fuel pumps and system issues. He has videos that detail how to check fuel pressure, the fuel regulator etc - it's pretty easy to do.

[DMil26SD]

"Let me discuss the fuel."

Any ethanol in the old or new fuel? Under certain conditions, it can create gunk, and cause the symptoms you described.

I have never put any ethanol fuel in. I’m the second owner, I have no clue what the previous owner did.

[DMil26SD]

If you want to diagnose any of this yourself, check out www.mancavemechanic.com, he has done quit a bit of work around the VP fuel pumps and system issues. He has videos that detail how to check fuel pressure, the fuel regulator etc - it's pretty easy to do.

Thanks, I did look at his website last year when I heard a high pitched whine. I thought the pump might be failing but the sound went away.

[bruceb58]

I have run ethanol fuel for the last 20+ years in both carb'd and fuel injected boats and I have never had an issue with it. It's not the bugaboo that people make it out to be.