Won't run :(

[Boarder_X]

So my boat starts, and then runs great for about a min or two. Then it dies. It was doing this, the last day of the season last year. So, now that spring is coming, I thought I'd try and get it running. I changed the cap and rotor and the fuel filter. I am in the process of changing the oil. I have the 5.7L carburated.

Next I am going to change the spark plugs, but I know that won't fix the problem. ... Just time to change them.

Could the carb need a rebuild??? If so, how do you do that? I was going to try and do one a couple years ago, with my old boat, but knew instantly, I was in over my head.

Thank you!!!!

Robb

[gman]

How old is your boat?

[Boarder_X]

It's an 03.

[gman]

Three years is a bit soon to be working an a carb. in my opinion. I had two boats with a carburator one for 9 years and the other boat for 20yrs and never once touched it. Boats ran fine. Just my experience. You may have water in your fuel!

[Boarder_X]

Hmmm.. Good point. I started it yesterday, and it was smoking quite a bit.

Thanks. I'll run some of that water remover through the tank, and see if that helps.

Thanks again.

[scootc]

Mine had a bad pick up module that would let it start (sometimes), then barely run or die within a few seconds. This is the module in the bottom of the distributor and picks up the rotor position. Once I pulled it out I could see it had corrosion on it. It was real easy to change but the part itself was a bit pricy.

[Boarder_X]

scootc

I saw that piece number 6 was really corroded. Is that the piece you are referring too? .... It is listed as $56 on mercury's website. I would have replaced it earlier, but didn't, know what it was, or what it did.


Thanks,

Robb

[scootc]

That's the one! Lee might be able to back me on this, but I'd be willing to bet that's where your problem is. Let us know!

[condor86]

Hello all,

Hey it can get awfully xpensive trying new parts to fix the problem....besides the mentioned part, what about a fuel problem? I have had lots of trouble with Mercruise fuel pumps, and what you described seems like it could be fuel. There are check valves that could be frozen, there are 2 fuel pumps i believe on your motor that could be faulty, or even something as simple as a pinched fuel line. I have even seen the fuel pickup in the tank deteriorate and not suck fuel.

When your boat dies is there fuel in the fuel filter?

I agree that it is too soon to rebuild a carb.

Hopefully ssomeone else can chime in on this one,,,,,

[lee]

Have you changed the fuel filter, water separating filter? If the boat has not been properly winterized over the years the fuel could be starting to gum up the jets in the carburetor.

Most of the time when the module in the distributor is bad the boat will not start at all, it will just turn over with out any fire.

Is the problem happening when the engines is cold, hot or both? If it is when the engine is warm and you have let the engine sit for a while the fuel could be vaporizing in the line. Check to see if the fuel line is running close to the exhaust.

[Boarder_X]

I just changed the fuel filter two days ago, when I changed the cap and rotor. It had fuel in it.

How do I trouble shoot fuel pumps?

This whole problem started when the motor had been siting for about 2 hours.

I haven't checked yet, but how close is close to the exhaust? If that is the cause, how do I secure the line, so it won't move again? Can I "zip tie" it to something?

I changed the oil today, and haven't had a chance to start it up agina, to see if the sensor worked. Also I haven't had a chance to run water remover through the tank.....

I do REALLY appreciate all the help though.

Thank you!!!

[TeamAllen]

I had a similar problem. I have TB fuel injection though, not carburated. I did the tune-up with my son. Replaced the cap and rotor along with everything else. When we put it in the water it would start, run for a litle bit and start dying. No matter what I did with the throttle, pumping it would have no effect on the stalling.

The only item I left to my son, was tightening down the distributor cap. So, that's the first place I started troubleshooting. I loosened it, checked the rotor, looked around inside and made sure everythig was seated properly. It did the trick! I don't think it could of been off by much, but that's all I did and it has worked fine ever since. Luckily the boat ramp was slow and we were fast.

[waterbugs]

I had a similar problem on an 01 22i with the 330 hp mercruiser. The dealer told me about the distributor pick up but I really felt it was a fuel problem since it only happened after the boat was warm and sat for about 1 hr. I contacted Mercruiser and provided them with a description of the problem and my engine type and serial number. There was a recall for my particular power package and they paid for the repair which was an additional fuel pump located at the water separating fuel filter. The problem was a "hot soak" issue where the 1 fuel pump provided could not overcome fuel vaporization issues. The dealer told me they had never had a Tige vapor lock. Also during my investigation I found out that fuels sold in the US from Sep-Oct to Mar-Apr are actually different in regards to the additives used which affect fuel volatility. In my particular case I had filled the boat in Mar and it ran just fine during the colder weather. However, when I tried to use the fuel up during a hot day in May the boat would not run after the "hot soak". After it sat for a few hours it would run just fine until it was turned off again when the problem would resurface. Boat would start and run until a load was applied then it would shut down acting like it had run out of gas........engine is a 350 mag mpi.......no problems since repair.

[Boarder_X]

Seems to run now

I replaced the fuel pump. It took a while to get it primed, but I think it's running now. I had it hooked up to the hose, for quite a while, and it was running great.

I was hoping this wasn't the problem, because they are pretty expensive, but oh well.

Thanks to everyone that helped out, and now.... It's time for summer!!!!!


Robb

[gman]

Was the boat out of warranty. Do you have a MP engine? I understand that the warranty is 3 years for the MP and I would think that if its the fuel pump its covered, but I may be wrong? It also depends when in 03 your purchased it!