my merc. 5.0 left me stranded.....twice

[jkseahorse]

I have a 2000 Chapparal with a mercruiser 5.0 liter with EFI. This is my first boat with an inboard motor and we just got it this year so I am just learning. It starts and runs great then craps out and wont start. Like last Sun. it started fine and we tubed for about 1 and 1/2 hrs. Then stopped to swim and add air to a tube. I started up proceeded to throttle up and in mid throttle it lost power and died. Tried to restart and it ran for 5 seconds and quit. While running for this short bit the engine seemd to "surge" fast, slow fast, slow etc. then died. Then the more I tried to restart the more it didnt want to run. I opened the engine compartment and it seemed rather warm. But engine never read hot. Would this be a vapor lock issue. Checked the water seperating filter and no water in it to speak of. Hooked it on the muffs the next day (after being towed in) and it started up and ran fine. This same thing happened one time previously this summer with the engine "surging" for a few seconds before finally dieing. I called local marine mechanic and he said sheck the anto-siphon valve out of the fuel tank, and actually punch the ball and spring out and get rid of it. Im hesitant to do this as Im sure it was put there for a reason. I did check to see if it was stuck and it seemed to function well. Also checked the fuel line from tank to filter and it was clear. The first time it did this I took it out the next day and it again started up on the water and we ran fine all day. What do you guys think. I havnt ran the blower much and I know at the last fill up I put in some gas with Ethanol 10% 87 octane. Yeah the cheapest stuff. I havent experienced vapor lock in an engine before, but from what ive read it sure sounds like it could be the problem. As always any advice is greatly appreciated.

 

[dvan1901]

Re: my merc. 5.0 left me stranded.....twice

Have you changed the fuel filter just to be sure? When you press the valve on the fuel rail, are you getting pressure and fuel coming out? When you turn the key to "on", not "start", are you hearing the fuel pump spin up...everytime. Changed the spark plugs lately? Just a couple things I would look at first. Others will chime in with a few other things to check out.

 

[DaveM]

Re: my merc. 5.0 left me stranded.....twice

I called local marine mechanic and he said sheck the anto-siphon valve out of the fuel tank, and actually punch the ball and spring out and get rid of it.

It sounds like you need to find a new marine machanic. The antisiphon valve is a USCG mandated part used to prevent gas from being siphoned into the bilge in the event of a fuel leak.

Dump the contents of the fuel filter into a clear container to see whether there is water present. Change the filter if it is not yet been done this season.

 

[Bondo]

Re: my merc. 5.0 left me stranded.....twice

I have a 2000 Chapparal with a mercruiser 5.0 liter with EFI. This is my first boat with an inboard motor and we just got it this year so I am just learning. XXXXXXXXXXXXXX. XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX.XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX.XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX.XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX.XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX.

Ayuh,..... Ever heard of a Paragraph,..??

Best I could decipher is you have a Fuel Delivery Issue,.... Like Dave,+ Dvan said,...
Check,+ Change the Fuel Filters....

 

[jkseahorse]

Re: my merc. 5.0 left me stranded.....twice

Thanks for the advice. No water in the fuel filter but I went ahead and changed it anyway. It also sounds like the pump is spinning each time. Ill check the valve on the fuel rail next time out. Sorry my original post was so long. I thought background info. might be helpful in diagnosing the problem.

 

[QC]

Re: my merc. 5.0 left me stranded.....twice

I thought background info. might be helpful in diagnosing the problem.

It is, but some of us need punctuation to comprehend . . . I'm just sayin'

 

[TilliamWe]

Re: my merc. 5.0 left me stranded.....twice

Could be vapor lock, I suppose. Try running with the bilge blower on all the time. Or lift the engine hatch whenever you stop. If that makes it run better, then it was/is vapor lock.
No reason to apologize for running 87 octane in your engine, that's all it needs. 10% ethanol should not be a problem either.

 

[bruhaba]

Re: my merc. 5.0 left me stranded.....twice

You my friend, have vapor lock. I have a 4.3MPI Merc.....does the same thing. They are very sensitive to gas with ethanol. I ran for two years filling up my boat at one place and never had a problem. Filled it up at a different gas station (I assume with ethanol mixed in) and my boat will do the bog, stall and no start everytime I get it warmed up and let it sit.

I've tried running the blower all the time, opening the hatch after you shut it off etc...doesn't work...Have to wait 3-4 hrs before it will fire and stumble through the bubbly fuel. It helps if you push on the schrader valve and keep cycling the pump while letting the bubbly fuel out on a paper towel or something but then you have fuel vapors everywhere and stink like fuel for the rest of the day.

THE SOLUTION: Merc knows about this issue(they really pissed me off) and if you bring it to a dealer, they might fix it for you for free if you complain enough and are under warranty. My dealer said Merc would only cover the parts and not the labor because it is an "environmental issue due to the ethanol in the fuel", they then told me it is 4 hrs of labor. End of the day they gave me the boost pump kit. PN# 862264A 7

It is just a low pressure electric fuel pump and additional filter so that it will feed your high pressure pump. It will not solve the vapor lock and stumbling after it has been sitting, but it will likely get the boat started again.

My argument to Merc is, when they stopped having leaded gas, did Auto makers say "too bad, find gas with lead in it" or did they make the auto engine better(hardened valve seats, better materials) so that it would work with what is available. Sorry to any boat designers out there, but the marine industry is totally half assed on a lot of stuff compared to automotive. I get so pissed thinking about the fact that my 2007 new MPI boat won't start reliably and is under warranty and yet they say "not our fault, it's the environmental changes" What a crock!


Bottom line: Find a gas station without ethanol and stick to it. If you can't do this, don't let the boat sit too long without starting it, especially if ambient temps are high, run the blower, lift the hatch yadda yadda.... When it sits, the fuel cooler becomes a fuel heater after it heat soaks and it vapor locks.

 

[jtybt]

Re: my merc. 5.0 left me stranded.....twice

Also, a well known issue with the 4.3 is it runs hot and requires a cool down running period. Let it idle for at least 5 min to cool down before shutting off.

 

[BIGALF]

Re: my merc. 5.0 left me stranded.....twice

My 5.7L EFI did the same thing but it wasn't a vacum lock. It was a screen inside the fuel tank pick up tube that would clog when I ran with a half full tank of gas. This caused the junk in the bottonm of the tank to mix in with the fuel and clog the screen. I took the screen out and it now works fine. From what I hear a lot of boats do not have this screen in the pick up tube anymore. It would run fine on ear muffs because the boat was not moving and the fuel was not sluching around. try this first. it's the cheapest fix.

 

[Dshow]

Re: my merc. 5.0 left me stranded.....twice

? This thread is over a year and a half old...

 

[panther0876]

Re: my merc. 5.0 left me stranded.....twice

? This thread is over a year and a half old...

Thats ok!! Its good for others like me who are having the same problem and are looking for help.