Announcement

Collapse
No announcement yet.

Help I'm stuck. 2004 21i with a Marine Power 5.7 L

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

    Help I'm stuck. 2004 21i with a Marine Power 5.7 L

    Well, I've been trying to get this new to me a boat (the boat probably sat for a while before I got it), and while I've fixed many of its issues (thanks to help from this forum) I'm currently stuck. I've learned a ton and as I've moved forward I have more information, but I just feel stuck. Here is my current issue. I can start and idle no problem on a fake lake. I can RPM up to about 2k with no problem. After some time the engine starts getting hot. In the water, I can keep the RPM up and idle with no overheating issue. When I put in gear and go at idle speed also no problem. When I throttle up I can get up to speed but in about 30 seconds the engine loses power, drops RPM, and then usually dies. I can get it back to the idle state after that.

    Ok, so what I've done.
    Replaced: (fuel - all ethanol-free), fuel line, siphon valve, low-pressure fuel pump and insulated the fuel lines while they were off, the TPS sensor, ignition module/coil (this was a different issue), replaced perfect pass cable and unfroze step motor (also another issue), throttle and transmission cable (another issue) and steering gable (another issue). also cleaned up a massive rats nest of a wiring harness.

    Cleaned high-pressure fuel pump (Marine Engine Depot is out of stock or this would have been replaced as well), the carburetor looks clean and must have been replaced recently

    The fuel pressure at the fuel rail registers 60ish when turning the key and the pump kicks in. This drops back to 0 when the pump stops. When at idle it stays at 60ish. My next test is to see what this does in the water and identify what happens when under load.

    The ohms on the fuel injectors all read around the same between 13.5 and 15
    The plugs to the injectors all receive power
    When listening to the injectors they all sound like they have a regular "tap, tap, tap" at a high speed and all sound the same.
    I'm tempted to take the whole rail apart and clean along with cleaning the injectors but didn't know if that would be futile.

    Ok, so part of doing this project was to try and learn something. I can say I didn't know what a fuel injector or and engine coil was a month ago. Now however I'm at a loss for my next steps. I want to keep learning, but I need a nudge in the right direction.

    Thank you for your time.


    #2
    [mention]gumby [/mention] ok, I just assumed that because I have no problem in the water, that over heating on a fake lake was normal. I have gone through every hose and strainer up to the manifold and replaced the impeller.


    Sent from my iPhone using Tapatalk

    Comment


      #3
      @gumpy. Ok that is good to know. (The pressure should stay when turning key) I replaced the low pressure fuel pump, but can't get my hands on a high pressure pump. I'm testing with the fuel pressure gage in the lake this weekend.


      Sent from my iPhone using Tapatalk

      Comment


        #4
        I admittedly don't know this system, so I'm taking some shots in the dark. You have a carburetor? Not fuel injection? You have 60 psi going to a carburetor? I think that's your problem. 60 psi to a carb would flood it out so bad it shouldn't ever run.

        Comment


          #5
          I think he has a fuel injected 5.7L and the "carb" he referring to is actually throttle body.

          Comment


            #6
            Yes, it is fuel injected with throttle body.


            Sent from my iPad using Tapatalk

            Comment

            Working...
            X