Results 1 to 7 of 7
  1. #1
    Midwestrider's Avatar
    Join Date
    Jan 2014
    Location
    S.E Wisconsin
    Posts
    11

    Can mpems be intermittent? '97 787 starts randomly. Runs great once started??

    My '97 SPX usually never gave the double beeps before starting. It would start awesome and thats all I cared about.
    This spring though it did not start. After several hits of the switch I would get 1 short and 1 long beep or just one long beep. After getting those beeps I could usually get it started by removing and reattaching the tether and hitting the start switch. After it started I was good to go for the duration of my ride. I could start and stop fine. Only after the ski sat for awhile or overnight I would have the same nonstart problem. Leaving the tether in the exact same spot after a ride and going back the next day would result in the same issue. So I did't think the tether connection was the problem.
    The gauges spring to life and the vts works with no tether and I hit the start switch. It also does the same with the tether connected.
    After reading through all the threads I could find relating to my intermittent start. I did the following:
    -installed new Odessey batt.
    -Cleaned contacts on both my tethers and dess post
    -disconnected all connectors going to the mpem and inside the mpem, cleaned with contact cleaner, used emery cloth and reseated connections. Did the same in rear electric box and connector to stator.
    -ran a new wire from mpem ground directly to battery neg.
    -removed connector inbetween dess post to mpem box and connected wires directly.
    -cleaned fuse holders in rear and front boxes and verified fuse sockets with meter.
    -connected new radio shack beeper to the purple and tan wires (no change in beeps)
    -Replaced start relay with new one.
    -Replaced the dess post with used one from salvage yard (hope it's not bad) although both posts check out fine voltage and continuity wise.
    -Start/stop switch continuity showed the switch was good.
    -Both tethers magnets are strong enough to lift a small/medium sized screwdriver.
    - tethers ohm out well under 10 ohms (sit at about 9 ohms).
    Non of the above changed anything with the problem.
    I don't think the keys need reprogramming because once I get it going it works fine for that riding session.
    One thing a little strange is sometimes after releasing the start switch the gauges power down immediately with the tether connected and sometimes not.
    Moving each wire at each connector and each entry point into the mpem bought nothing.
    It's almost like the mpem needs to be awakened to recognize the tethers.

    Not sure what to try next. Please help.
    p.s. anyone near S.E Wisconsin with a good mpem to help me verify before buying one


  2. #2
    Waterluvr's Avatar
    Join Date
    Mar 2015
    Location
    Northern Indiana
    Posts
    478
    +1
    69
    The dess post or one of the initial required inputs from the harness is usually the culprit, I've posted many detailed threads over the years on diagnosing faulty mpems and wiring if you search them out you'll find more in depth information than you ever cared to know about testing and diagnosis of mpems, wiring and hardware.

    But you really can't beat pulling the mpem out and performing a bench test, swapping mpems is a bad idea until a diagnosis of fault is made less you kill a 2nd one that way if a harness short is taking out the 5 amp diode circuit in the module.

    Here in the shop I bench test anything I'm working on and hook it right up to the laptop and run it through the paces but you guy's at home turning your own wrenches without expensive tech to do that can still hook up power and ground supplied by a short protected power source followed by a dess post and buzzer when your programmed key is placed on the post you should get two beeps from the module and that signals the security is working and unlocking the ignition.

    From there if it's working ok you can wire in a momentary switch and test for output to the starter relay, that gives you piece of mind that the mpem is working 100% to the point it is fully capable of unlocking the security and cranking the engine so you'll know to look for problems in the harness or other hardware.

    If you don't have the shop manual for your ski with the wiring diagrams send me a PM and I'll host it for you to download for free.
    Last edited by Waterluvr; 08-20-2016 at 03:13 PM.

  3. #3
    Midwestrider's Avatar
    Join Date
    Jan 2014
    Location
    S.E Wisconsin
    Posts
    11
    Thanks waterluvr,
    I'll dig in to find your mpem diags.
    Last night I found that it would crank over and start after doing nothing other than hitting the start switch 25 + times? After letting it sit for 10 minutes I would have to do the same thing to get it to crank over. The stop switch meters out perfectly.

  4. #4
    Waterluvr's Avatar
    Join Date
    Mar 2015
    Location
    Northern Indiana
    Posts
    478
    +1
    69
    Dess posts, mpems and their functions will defy every commonly accepted norm of pass/fail standards of accepted electrical testing sometimes. Your dealing with a module that works on Maxim one wire protocol and the low voltage circuit that uses the white wire will sometimes work intermittently with a dess post that tests fine, identical to another that works 100% in conjunction with the module.

  5. #5
    Midwestrider's Avatar
    Join Date
    Jan 2014
    Location
    S.E Wisconsin
    Posts
    11
    Waterluvr, How far from Racine Wis are you located?
    Thanks

  6. #6
    Waterluvr's Avatar
    Join Date
    Mar 2015
    Location
    Northern Indiana
    Posts
    478
    +1
    69
    Quote Originally Posted by Midwestrider View Post
    Waterluvr, How far from Racine Wis are you located?
    Thanks
    We service primarily large vessels in Lake Michigan harbors, my closest destination on the West side of the Lake is the port of New Buffalo and we go as far north as Saugatuck/Douglas but Racine is almost three hours away. Were actually booked solid for the remainder of the season and are going to discontinue 2 stoke PWC service after this year for any new customers these machines are getting to the age where most repairs exceed value and any major repairs are well into the range of late model low hour 4 stroke machines.

    We'll still do some basic maintenance, make keys and offer diagnostic service and BUDS reports for DIY guys that want to turn their own wrench but these machines are well into the DIY stage of obsolescence at this point it doesn't make sense to rack up a bunch of billable hours on shop tickets for the low resale value they have anymore.

  7. #7
    dan725's Avatar
    Join Date
    Jan 2009
    Location
    northeast ohio
    Posts
    267
    yes, Ive seen them slowly die.

Thread Information

Users Browsing this Thread

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

Similar Threads

  1. Can a bad spark plug be intermittently bad?
    By Pointhunter75 in forum Kawasaki How To & FAQs
    Replies: 11
    Last Post: 05-17-2016, 09:52 AM
  2. Replies: 0
    Last Post: 06-27-2014, 03:55 PM
  3. 2002 Polaris Virage i won't start. Can CODES be MANUALLY accessed?
    By zardoz in forum Polaris Open Discussion
    Replies: 2
    Last Post: 12-29-2011, 11:16 AM
  4. WTB Need a mpem for a 97 xp 787 with dess key
    By onefastgpr619 in forum Sea Doo Classifieds
    Replies: 10
    Last Post: 06-21-2010, 11:16 PM
  5. Oil injector lines 97 700slt can they be crossed
    By crashem in forum Polaris Open Discussion
    Replies: 2
    Last Post: 06-30-2007, 02:59 PM

Posting Permissions

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