5.0mpi wont stay running

jimmyjr

New member
hi all,i have a 2003 5.0 merc mpi/alpha one,i have put about 3 hrs on motor then ran out of fuel.put fuel in then ran boat again for about another three hours.i put the boat away and it ran great for about ten mins.then just died.i pulled the water/sep fuel filter,and it was full of a white milky substance.i then checked my tank.tank was fine as well as tank pickup and check ball valve blew trough the line and all was good.i couldnt get the boat to run again.so i checked the pump.all was good tried again nothing.so today i tried to run the boat on an outboard tank.i could get the motor to run.but it would not idle.and would not stop backfiring through the intake[sounded like it was running on 5cyls and boat would not plane,no power] im not trying to get a freebie here.my local dealer has no clue nor does he have the proper scan tool.he is agreat guy just mainly deals w/outboards up to 60 hp.i am in saskatchewan canada,and my boat is a 202 baja islander.any help is greatly appreciated.and if i can pay someone for thier help iwill gladly do so.i have been around boats forever but i am stumped.please help thanks
 
I'm guessing gunked up injectors. As much as you like your local guy, a service tech these days needs the proper scan tools. I purchased Diacom Marine so I can see whats going on for myself. Good luck.
 
thanks for the reply i am thinking injectors as well.is there someone on yhe board that sells the diacom marine scan tool.
 
yes i filled the filter to the top,can someone let me know the best step by step way to clean the injectors for this engine.i really need the help,we have some big family plans and the boat is the centre of the fun,like i said im willing to pay i just dont have the dealer support in my area,thanks to the guys who have replied so far
 
There are aerosol cans that screw onto the Schrader valve on your fuel lines. That is about the easiest and cheapest way to attempt cleaning. Not the best most complete way, but cheap and as easy as it gets! Try that first, then yanking them out...
 
I can get a #M 3 stage cleaning kit that does the fuel system
Let me know I can ship it to you!
I'm not sure where you are with your project
 
If the fuel cleaner kit doesn't do it, there is a Company in Florida that test and rebuilds injectors for about 50 bucks an injector. The company is Flagship Marine Engine Co. in Punda Gorda Fla. I don't have the phone number but it should be east to find on line
 
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