GSX mpem issue

[Nilo]

I have a 1998 gsx ltd. I have a starter issue, however I now believe it to be the linked to the mpem unit. I am a motor mechanic so have a good idea of what I'm doing here.
Mpem will only supply 10 volts to the starter solenoid. I have measured this voltage 2 inches from mpem unit on the solenoid feed wire and at the solenoid itself, 10 volts. In the process of getting this far I have fitted new starter, starter solenoid, all new battery cables, earths etc New start/stop switch. Currently have a new ride on mower battery of 300cca rating installed. I have double checked all earths and soldered all connections where possible. I have run an earth from the battery negative to the earth post in the starter relay box. Alternator charging @ 13.5 volts.
The 951 carbed motor runs extremely well when running but it's the starting. The starter works for 3 seconds, then stops, press start button, works a few seconds then stops, works, stops etc etc. Off on anything from 2 to 6 seconds. If I short circuit the starter solenoid across the posts and push the start button, the ski starts immediately. I am only measuring 10 volts at the starter solenoid activation wire. I feel this is why the starter works and stops. Press the start button and starter works and stops etc. I just keep going through the same cycle until the motor starts.
Any suggestions?
I think it's the mpem, not supplying 12 volts to the solenoid causing the solenoid to drop out? I'm thinking of replacing the mpem with a Arieltek unit? Has anyone
purchased or used the Arieltek mpem? Seems like it works with any dess key? Price is right, but quality. I have never worried about non original parts. Any reviews.
Thank you.
Neil.

 

[artr]

After looking at the schematic I would try a few things. Remove connector #3 from the MPEM and check male and female sides for dirt/corrosion, especially pins 3-26 (12V to MPEM), 3-17 (solenoid drive signal from MPEM) and 3-16 (ground from MPEM to ignition coil base then to solenoid base). Do the same for the connector at the rear electrical box. Also if there is a bolt at the base of the ignition coil that has several grounds connected to it, remove it and clean the bolt and all ground connectors and reassemble.
Does the 10V you measure on the solenoid drive input stay at 10V when the starter cuts out or does the 10V disappear when the starter cuts out?

 

[Nilo]

After looking at the schematic I would try a few things. Remove connector #3 from the MPEM and check male and female sides for dirt/corrosion, especially pins 3-26 (12V to MPEM), 3-17 (solenoid drive signal from MPEM) and 3-16 (ground from MPEM to ignition coil base then to solenoid base). Do the same for the connector at the rear electrical box. Also if there is a bolt at the base of the ignition coil that has several grounds connected to it, remove it and clean the bolt and all ground connectors and reassemble.
Does the 10V you measure on the solenoid drive input stay at 10V when the starter cuts out or does the 10V disappear when the starter cuts out?

 

[Nilo]

Thank you for the reply.
I have cleaned the earthing wires on the coil bolt. There's about 3 or 4.
I also made up a stand alone wire from battery negative to that coil bolt. (A wire about 14" long). This gives a direct earth to the coil bolt. So we can count that out.

When starting, there is only 10 volts activating the solenoid. When the starter drops out, there is still only 10 volts at the solenoid wire. I believe there should be 12 (at least) which is what I believe is causing the solenoid to drop out resulting in the starter just stopping.
There is only 10 volts coming out of the mpem during starting. Measured at the mpem. Again, I believe that should be 12 volts give or take a little. That counts out a corroded or damaged "mpem to solenoid wire".

With volt meter attached in parallel with solenoid wire during starting It shows and stays at 10 volts.

The battery voltage into mpem is generally about 12.8 give or take a little so mpem getting the power it requires. Again checked with accurate voltmeter gauges.
I have fitted a new 300cca battery from a ride-on mower so battery okay.

If I short the two main solenoid battery posts and at the same time press the stop/start button. Instant start, beautiful idle and runs very well.
As I live on an isolated atoll 6 hours Sth of Hawaii, it can at times be difficult repairing and/or getting parts.
I think I will install a stand alone second solenoid for starting thus doing away with a screw driver across the solenoid. (Not the safest method). I will buy a new mpem if necessary but want to eliminate all else.
Have you any experience with a Arieltek mpem? No coded key needed.
Cheers and thank you.
Neil.

 

[Nilo]

Artr.
Overlooked one of your questions being If there was 10 volts still present at solenoid when starter drops out and finger still on start button. I'm sure it was not but
I will double check this and get back to you.

Edit::
Checked as above and find the voltage at the solenoid is between 7 to 10 volts, then voltage fails causing the solenoid to drop out. Same result is obtained if I measure voltage 2 inches from mpem plug thus indicating it's not the solenoid wire corroded and possibly failing.
My next check will be to see if I have a constant 12+ volts going into the mpem when I push the start button. I'm positive I checked this but I'll double check later.
Cheers.

 

[artr]

I also think the solenoid drive signal out of the MPEM should be closer to 12V but I do not know that for sure. Did you at least try cleaning connector #3. since I think your MPEM is potted and cleaning the connector pins is all you can do to insure the voltage drop is not occuring at the pins on the connector, before the external wire.
I do not have any experience with aftermarket MPEMs.

 

[Nilo]

I also think the solenoid drive signal out of the MPEM should be closer to 12V but I do not know that for sure. Did you at least try cleaning connector #3. since I think your MPEM is potted and cleaning the connector pins is all you can do to insure the voltage drop is not occuring at the pins on the connector, before the external wire.
I do not have any experience with aftermarket MPEMs.

Thank you artr. Appreciate the help. I think a new secondhand mpem is the way forward. Quite keen to see if anyone has hands on experience with the mpem made and sold by artieltek.
Cheers.

 

[artr]

Most of the posts I have read here were not complementary of aftermarket MPEMs and recommended using original Seadoo parts. You may want to contact the moderator of this forum, mikidymac. He might know something about the artieltek units or point you to someone who has used them. Good luck.

 

[Nilo]

Thank you artr. Appreciate the help. I think a new secondhand mpem is the way forward. Quite keen to see if anyone has hands on experience with the mpem made and sold by artieltek.
Cheers.

Thank you artr. Your comments have helped and are appreciated. Your comments have reaffirmed by suspicion of faulty mpem.
Have a great 2024.

 

[WhiskeyD]

I've got a 98 GSXL mpem if you need one

 

[Nilo]

I've got a 98 GSXL mpem if you need one

Yes, I'd be keen to negotiate purchase. I live in the Cook Islands so mpem would need to have the Tess key as it is impossible' for me to have one recoded here. I will be in NZ 15th February for about 3 months. I can pay cash or internet if we come to agreement. I bank with ASB Westgate.
Cheers. Neil.
EDIT: So sorry, I thought you were in New Zealand. I am on a NZ Sea-Doo forum and thought this was it so got mixed up.
Neil.

 

[WhiskeyD]

PM'd you

 

[Nilo]

PM'd you

Haven't received pm as yet.

 

[Nilo]

PM'd you

Delivery address would be to Auckland New Zealand. Postage of items I've bought off eBay is generally reasonably priced and surprisingly fast.
I'll get back to you. I'll be in NZ in 3 weeks time.
I've got to reiterate though that dess key must be programmed to work with that mpem as it is impossible for me to have key programmed here. I live 6 hours flying time sth of Hawaii on an isolated atoll.
Cheers.

 

[pros600]

Artr.
Overlooked one of your questions being If there was 10 volts still present at solenoid when starter drops out and finger still on start button. I'm sure it was not but
I will double check this and get back to you.

Edit::
Checked as above and find the voltage at the solenoid is between 7 to 10 volts, then voltage fails causing the solenoid to drop out. Same result is obtained if I measure voltage 2 inches from mpem plug thus indicating it's not the solenoid wire corroded and possibly failing.
My next check will be to see if I have a constant 12+ volts going into the mpem when I push the start button. I'm positive I checked this but I'll double check later.
Cheers.

did you measure resistance across fuses.i have seen internal corrosion on some

 

[Doug Overkill]

MPEM battles are awful. So hard to diagnose and I feel your pain. I do not know of the aftermarket brand you asked about. I was able to get a MSD 4255 enhancer to work on my 787 sea-doo motor and works great.

Finding a ‘good’ 25 yo MPEM is a gamble and getting harder everyday.

As far as the problem you describe I would add a standard automotive 4 wire relay to the ski. Use the 7-10v from the MPEM to trigger the relay which would pass full battery voltage thru to starter solenoid.

 

[Nilo]

did you measure resistance across fuses.i have seen internal corrosion on some

Tried that this morning. I used the Sea-Doo starter solenoid to activate a stand alone solenoid which in turn supplied 12 volts power direct to the starter. It all worked but same problem.
The power from the mpem drops down to maybe 7 volts thus the seadoo solenoid drops out and that in turn drops the added in stand alone solenoid.
Your idea was worth a shot but I think replacement mpem the only way. Artr has a couple for sale and I contacted him yesterday with an offer but at this stage, yet to hear back.
Thanks for all the help.
Cheers.

 

[Doug Overkill]

Tried that this morning. I used the Sea-Doo starter solenoid to activate a stand alone solenoid which in turn supplied 12 volts power direct to the starter. It all worked but same problem.
The power from the mpem drops down to maybe 7 volts thus the seadoo solenoid drops out and that in turn drops the added in stand alone solenoid.
Your idea was worth a shot but I think replacement mpem the only way. Artr has a couple for sale and I contacted him yesterday with an offer but at this stage, yet to hear back.
Thanks for all the help.
Cheers.

Good test but I think you over did the test relay using a full starter solenoid. One of the 4-pin (5 also works) relay that are like $2-5 at any auto parts stores. Most of those will pull closed with 8v and stay closed as long as you are above 5v.

Like these.
Bosch 0332019457 Mini Relay
Amazon.com

 

[Nilo]

Good test but I think you over did the test relay using a full starter solenoid. One of the 4-pin (5 also works) relay that are like $2-5 at any auto parts stores. Most of those will pull closed with 8v and stay closed as long as you are above 5v.

Like these.
Bosch 0332019457 Mini Relay
Amazon.com

Very good point and advice.
Yes, I used a spare (new) starter solenoid I have here. I think off an OMC 140 HP outboard.
I've got some of those relays here in the workshop so I will try one tomorrow.
Before retiring I had a scuba diving business here on Aitutaki, Cook Islands. Google it. In my quite extensive workshop there is all manor of spares for all manor of machinery.
Quite keen to get out and try your suggestion., but tomorrow.
Cheers, Neil.

 

[Mauide]

I have same problem ,did everything you did . Have gsx MPEM any one know if I can try that one in my gtx