Page 1 of 2 1 2 LastLast
Results 1 to 10 of 14
  1. #1
    BLYamaha's Avatar
    Join Date
    Jun 2017
    Location
    Minnesota
    Posts
    7

    03 MSX140 Starts but dies after only a couple seconds.

    Hi everybody! New to the forum but have read a lot of helpful posts on here! I'm working on a 2003 MSX 140. This spring it wouldn't start. It would crank but would not light the MFD, had no spark and the fuel pump didn't run when cranking. Determined it was a problem with the EMM and sent it in for repair. Got it back today and tried it in the ski. Now the MFD lights when you crank it and it starts right up however it only runs for a very short time (1-2 seconds) before it loses spark and I can't hear the fuel injectors clicking. If you crank it again it will not have spark/fuel. If you wait for the MFD to turn off and crank it again it will start/die again. I've worked on a few Ficht skis (Genesis and Virage) but this is my first MSX140. It seems like a bad LR503 Module to me but this ski doesn't have that unit. I unhooked the black/yellow wire from the kill switch and it didn't change the problem. The stator and CPS test perfectly. I checked the codes and the only code was 12, for the TPS that was unplugged. This one has stumped me. Any and all help would be greatly appreciated! Thanks in advance! -Brennan

  2. #2
    martincom's Avatar
    Join Date
    May 2010
    Location
    Brainerd, MN
    Posts
    622
    +1
    55
    Try unplugging the MFD. I'm wondering if there is something heating up in the MFD that is impacting the signals, such as the tachometer, from the EMM as it will run briefly after the MFD has gone into sleep mode.

  3. #3
    BLYamaha's Avatar
    Join Date
    Jun 2017
    Location
    Minnesota
    Posts
    7
    Thanks for the advice! I just went out and tried it but the ski won't start at all with the MFD disconnected; it just cranks. Does anybody know if there is a way to fool the EMM that the MFD is connected? Is it possibly a bad MFD or is it more likely that the EMM is still faulty even after being rebuilt?

  4. #4
    martincom's Avatar
    Join Date
    May 2010
    Location
    Brainerd, MN
    Posts
    622
    +1
    55
    Where are you located in MN? I have a spare MFD and a MSX140 with a good EMM. Do you have the service manual?

  5. #5
    martincom's Avatar
    Join Date
    May 2010
    Location
    Brainerd, MN
    Posts
    622
    +1
    55
    I performed a quick review of the wiring diagram and the MFD section of the service manual. I don't see anything where engine start/running would be dependent on the MFD being connected. I'm wondering if there is a power path being looped through the MFD due to a poor connection, splice or ground. I'd troubleshoot the issue further with the MFD disconnected.

  6. #6
    BLYamaha's Avatar
    Join Date
    Jun 2017
    Location
    Minnesota
    Posts
    7
    No I don't have a service manual for it. I'd like to find a wiring diagram for it but I haven't been able to find one anywhere. I'm down in the far southwest corner of MN. I thought it was strange to that it wouldn't start with the MFD connected. I'll have another look at the wiring. Thanks for your help!


  7. #7
    BLYamaha's Avatar
    Join Date
    Jun 2017
    Location
    Minnesota
    Posts
    7
    Well still working on this thing. Now it seems to start/do the same thing with the MFD unplugged but you need to wait the same length of time it would take for the MFD to turn off before it will start/die again. I got a wiring diagram and traced every single wire on the watercraft. They all ohm tested perfect with continuity where needed. All sensors/components seem to test fine. I would bet that the EMM is still faulty. I have access to a couple EMM's from different models. I believe one is off a 02 Virage. Could I plug that one into this MSX just to see if the problem is still there? Will it hurt anything on the watercraft? I'm not going to take it on the water with it; I just want to see if the problem changes. Also I have access to an EMM from a Kawasaki. I guess I have the same questions there. If anybody has any input on the matter I would love to hear it.

  8. #8
    Moderator HiPeRcO's Avatar
    Join Date
    Jul 2007
    Location
    Upstate NY
    Posts
    2,183
    +1
    151
    Quote Originally Posted by BLYamaha View Post
    Well still working on this thing. Now it seems to start/do the same thing with the MFD unplugged but you need to wait the same length of time it would take for the MFD to turn off before it will start/die again. I got a wiring diagram and traced every single wire on the watercraft. They all ohm tested perfect with continuity where needed. All sensors/components seem to test fine. I would bet that the EMM is still faulty. I have access to a couple EMM's from different models. I believe one is off a 02 Virage. Could I plug that one into this MSX just to see if the problem is still there? Will it hurt anything on the watercraft? I'm not going to take it on the water with it; I just want to see if the problem changes. Also I have access to an EMM from a Kawasaki. I guess I have the same questions there. If anybody has any input on the matter I would love to hear it.
    You can try a different Polaris EMM as a test to see if the engine will start and idle, but DO NOT run the engine under load or even let it idle for a long time with a mismatched set of injectors. Don't be surprised if additional EMM's also don't work, its best to start with a known good one (they can be rare I know...)

    I don't know about the Kawasaki EMM, never tried it.

  9. #9
    BLYamaha's Avatar
    Join Date
    Jun 2017
    Location
    Minnesota
    Posts
    7
    Thanks for the quick reply!

  10. #10
    BLYamaha's Avatar
    Join Date
    Jun 2017
    Location
    Minnesota
    Posts
    7
    Just tried the Virage EMM I have. I plugged it in completely and it failed to start but it always had spark, so progress. That box is for a twin cylinder and I know it has a problem so not surprising it didn't run. Then I unplugged the big plug from it and connected that to the original MSX140 EMM and it fired right up and ran using 2 EMM's so the EMM is still bad even after being "repaired". Thank you for everybody's help! Glad to finally have a definite answer!

Page 1 of 2 1 2 LastLast

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. Dying after running only a few seconds
    By jason.schoenrock in forum Polaris Open Discussion
    Replies: 2
    Last Post: 07-04-2012, 12:20 PM
  2. Replies: 3
    Last Post: 07-01-2011, 10:14 AM
  3. 1994 700ra Starts but dies
    By dfitz in forum Yamaha Old School Skis
    Replies: 3
    Last Post: 06-01-2011, 05:03 PM
  4. 96 xp starts but dies
    By XP537 in forum 2-Stroke Performance
    Replies: 9
    Last Post: 05-20-2010, 07:33 AM
  5. my jet ski starts but only when i prime it
    By mushroomhead8 in forum Polaris Open Discussion
    Replies: 9
    Last Post: 12-13-2008, 01:11 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •