Announcement

Collapse
No announcement yet.

having engine issues.. need a little help, Fuel or ignition. 350 mag mpi

Collapse
X
Collapse
 
  • Page of 3
  • Filter
  • Time
  • Show
Clear All
new posts
Previous 1 2 3 template Next
    #1

    having engine issues.. need a little help, Fuel or ignition. 350 mag mpi

    Got my boat back put of storage this year and Im having issue when running at high rpm. the boat cranks fine, idles fine, and accelerates fine.... but once im get to around 3500 rpm and run there for a few seconds the engine bogs down and loses power and will not regain it until the it idles back down for a few seconds. It varies on length of time and rpm but usually above 3200m but have reached 4500 but every time it will it will stall.

    I replaced fuel/water separator. did not help... I have pulled another in line filter and will replace it tomorrow. I crack the sep filter with engine running to see that it was getting fuel and it was getting fuel.

    today I pulled the tank and drained all the fuel...every last drop was bad. Im thinking this was mainly my problem... I have experienced the exact same issue with water in fuel on my v twin mud motor.

    but another concern i have is that my distributor was a but loose. I think I may have lost timing.. in fact I know i have since i moved it. before I go back out on the water I want to figure out how to time this thing. after research It looks as if I cant just hook up a timing light and twist the distributor like a truck. Is that correct? Is this something I can do or is it best to take it in to the shop. the manual says 0 deg. at idle??

    also wondering if I should go ahead and change plugs since i know ive ran it with bad fuel?
    Tags: None
    #2
    I would have thought the fuel first as well. Sounds like you probably found the main cause. Others will for sure, know more than I do. I think it depends what MEFI system you have for how to set the timing. I found this answer to read until some smarter TO members can help.
    Good Luck!
    http://www.justanswer.com/boat/884hn...-efi-mfei.html
    Mike Allen, Tigé owner since 1997

    Comment

      #3
      Also replace the anti siphon fitting at the outlet of the fuel tank to the engine, water in gas will destroy those things too. Unfortunately, you'll need a diagnostic computer to set the timing correctly or a timing tool offered by mercruiser. You have to get the motor warmed up, put the engine in base timing mode through the computer and it will advance itself to about 1300rpm, then set the timing at 0* on the marks, lock down the distributor, take engine out of base timing mode and call it good.
      Fixing everyone elses boat just so I can use mine...

      Comment

        #4
        what about the jumping wires method to get in service mode as mentioned in the above link.

        Comment

          #5
          If this is the right tool, it's inexpensive enough? I don't think I would mess with the potential for mistakes, probing the wrong terminal.
          http://www.amazon.com/Mercury-Marine...er+timing+tool
          Mike Allen, Tigé owner since 1997

          Comment

            #6
            Interesting on the jumper wire. Use the DTC connector cap and make sure you hook it up right but that will get you there, or $17 for the tool.
            Fixing everyone elses boat just so I can use mine...

            Comment

              #7
              I cannot find this dlc connector anywhere??? I have looked every where and can only find one 10 pin connector and it does not look like the ones pictured

              Comment

                #8
                If it's like mine it's inside a black box mounted on the rear of the engine. I'll see if I can find some pics?
                Mike Allen, Tigé owner since 1997

                Comment

                  #9
                  Maybe these will help? It's right behind the distributor.
                  Attached Files
                  Mike Allen, Tigé owner since 1997

                  Comment

                    #10
                    Yep I have nothing like that anywhere on my engine

                    Comment

                      #11
                      Is it a Mercruiser?
                      Mike Allen, Tigé owner since 1997

                      Comment

                        #12
                        mercruiser mpi 350 mag tow sports. 2002 model.

                        Comment

                          #13
                          I am surprised it's not in the same location. The picture I took has the cover of the black box removed. I had to remove a few screws to get it open.
                          Maybe take a picture of the back of the motor. As you can see the wires, in the second picture, coming into and out of that box are pretty hefty. You should be able to find those I would think?
                          Mike Allen, Tigé owner since 1997

                          Comment

                            #14
                            Maybe this picture might help? It looks like it's attached to the side of one of the exhaust manifolds.
                            http://www.justanswer.com/boat/29pr8...tige-fuel.html
                            Mike Allen, Tigé owner since 1997

                            Comment

                              #15
                              Originally posted by TeamAllen View Post
                              Maybe this picture might help? It looks like it's attached to the side of one of the exhaust manifolds.
                              http://www.justanswer.com/boat/29pr8...tige-fuel.html
                              yes i believe that is the ecm... and it is as pictured but there is no 10 pin connector just the the two plugs on the harness that plug into the ecm and to relays that hang next to it along with the fuses

                              Comment

                              Previous 1 2 3 template Next
                              Working...
                              X