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I thought I was done

etemplet

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This 2003 GTI has been a true pain for me. I've been working on it for a gentleman who probably shouldn't own a 2-stroke jet ski. :) Been up one side and down the other. He flipped it over a few months ago so now..... Electrical gremlins confirmed and I only know "what it isn't." LOL I've tested and swapped all the big stuff. This is gonna be one for the books when I find it. I'm gonna check the DESS post and the grounds in the rear electric box, then I'll move onto the wiring harnesss. This is one sneaky jet ski. :D :D
 
You haven't read my thread... I have the worst grimlin on my 1999 GTI... I thought I was done with it as well but I found someone selling their ski for a good price. I may buy it and keep swapping parts until I find that grimlin. Last assessment was likely it was the engine that was bad, even though it has good compression. I didn't want to spend on an engine to find out it was another grimlin but likely its the engine.
 
Engine is easy to check. I've fought my share the some are down right difficult but.... once you find it, you understand exactly what it was doing and why. I haven't worked on this one yet this week but I'm gonna swap the DESS first thing. There are only 3 things left. DESS, Rear Electrical box, or bad wiring harness.

I found an issue with the push pin on the MPEM. When I wiggle the wire close to the plug the hold out realy clicks off and on. I don't know if I was deflecting the pin and breaking the contact or of there is a problem with the wire. Looks like a ground When I insert the key though, I hear the hold out relay clicking so that is working. I don't think the MPEM is talking to the KEY. MIght be a bad key but its pretty new. I had a lot of trouble getting my Candoo to talk to the MPEM. We'll see.
 
The engine compression is at 130, the jugs were warped and a couple of member stated that warped jugs could cause the weird problems i am having, so it's just an assessment that my engine's bad base on forum members opinions. I may agree because i took the top end apart and resealed it after having starting issues and the ski ran great for 40 minutes then stopped working again.
 
Spent an hour chasing wires and plugs. Now I'm sitting with the wiring diagram. Gonna be me and the multi-meter this afternoon. I'm not finding anything. I'm leaning more and more toward a bad DESS post or something up front. Lots of splice wires up there. When I insert the key (I've tried 2 keys with the same response, nothing) I hear the Holder Relay activate and get nothing else, no beep, nothing.

I'd really like to know which wires enerigize the MPEM and wake it up. I can't find the DESS test information in the 2003 manual but I'll figure something out.
 
Spent an hour chasing wires and plugs. Now I'm sitting with the wiring diagram. Gonna be me and the multi-meter this afternoon. I'm not finding anything. I'm leaning more and more toward a bad DESS post or something up front. Lots of splice wires up there. When I insert the key (I've tried 2 keys with the same response, nothing) I hear the Holder Relay activate and get nothing else, no beep, nothing.

I'd really like to know which wires enerigize the MPEM and wake it up. I can't find the DESS test information in the 2003 manual but I'll figure something out.
Sounds like a lot of work. I'd likely try to buy a used wire on ebay since the wires are already crap and maybe get those ebay
 
Seadoos don't respond to throwing parts at them. You have to find out "why". As of yet, I have not found anything but I'm finding out what it isn't. :D
 
Seadoos don't respond to throwing parts at them. You have to find out "why". As of yet, I have not found anything but I'm finding out what it isn't. :D
🤣🤣🤣 Yo that's so funny... I tried that method of just throwing parts at it since they were so cheap and still ended up with a ski that refused to start. I was ready to just throw an engine but the price stopped me...

The problem I had with my ski, Every part I tested was "bad" but after changing the part, it wasn't the reason it wasn't working right. Example, my rotary valve cover clearance was .540mm when the proper spec was supposed to be .300mm, with .350mm being the max clearance or it would not start. Got my cover milled and to fall within spec and it still wouldn't start, lol... I was like wtf!!! check out my thread for the whole story, it's called "fact check me" or something like that...
 
I got this one going but it's strange. I bought a spare MPEM for it and programmed a key. I had trouble but it was working fine. Then BOOM.... nothing so since it was working I began testing everything I hadn't checked. Finally I swapped back to the old MPEM and Bingo... two beeps starts and runs fine. I'm not calling it done. They are sneaky. :D
 
Seadoos don't respond to throwing parts at them. You have to find out "why". As of yet, I have not found anything but I'm finding out what it isn't. :D
I had a 2007 waverunner with an 1100cc 4-stroke that had one wire that had oxidized in the middle. No cuts or abrasions in the insulation, both ends were fine, and when testing with an ohm meter it had high resistance. Removed the wire from the harness and it felt lumpy about 12" from one end. cut it in two and it was powder inside. How it got that way, I don't know. Testing with an ohm meter at least one end of the wire must be disconnected.
 
I had a 2007 waverunner with an 1100cc 4-stroke that had one wire that had oxidized in the middle. No cuts or abrasions in the insulation, both ends were fine, and when testing with an ohm meter it had high resistance. Removed the wire from the harness and it felt lumpy about 12" from one end. cut it in two and it was powder inside. How it got that way, I don't know. Testing with an ohm meter at least one end of the wire must be disconnected.

I had the same problem with a Yamaha I worked on for a friend. I tested the wires (one was going to the starter) and I got 12 volts but like your problem the wire broke down internally and couldn't carry the amperage needed to activate the circuit. I had the same problem with a XP 787 rear electrical ground. I now have a "megger " but have not really used it on the jet skis. It should identify such issues and would come in handy. So many wires though. I guess all I would have to do is connect the megger wires to each end and crank it and it would tell me the condition of the wires. I need to read up on it to determine a boundary ready that would indicate a problem.
 
I had the same problem with a Yamaha I worked on for a friend. I tested the wires (one was going to the starter) and I got 12 volts but like your problem the wire broke down internally and couldn't carry the amperage needed to activate the circuit. I had the same problem with a XP 787 rear electrical ground. I now have a "megger " but have not really used it on the jet skis. It should identify such issues and would come in handy. So many wires though. I guess all I would have to do is connect the megger wires to each end and crank it and it would tell me the condition of the wires. I need to read up on it to determine a boundary ready that would indicate a problem.
This reminds me of something that might help somebody.... The rear electrical box, in this case it was on a 2000 GTi,, there's a 15 Amp fuse, and a push together connection that powers the MPEM when the engine is not running. My fuse receptacle had that oxidation growth down inside of the contacts, and the push-fit was lightly oxidized. I was not getting the beep beep until I cleaned both. After cleaning I applied dielectric compound to the contact areas before re-connecting. This dielectric compound is nothing more than silicone grease, and is an insulator, but as tightly as the contacts fit, that wasn't a problem. I guess a better way would be to make the connection first, and then apply the grease to keep moisture out. the stuff is great for rubber O-rings too.
About copper wires that oxidize within the insulation.... what makes it start? Saltwater is one way. How it gets so far into the insulation without either end of the effected wire being infected is a mystery to me. Yes, a "megger" would sure be a good thing to use. I remember seeing submersible cable for an oil well being tested with something similar, and I believe it induces a voltage into the conductor being tested, then measures the current loss or voltage drop.
Another possible high resistance connection on Seadoos is the male/female connectors crimped onto the end of the wires. They aren't soldered, just crimped, and are worthy of a visual when troubleshooting electrical issues. Also are the pins on the MPEM connectors, and also on the MPEM, the slots where the fuses plug in.
 
This reminds me of something that might help somebody.... The rear electrical box, in this case it was on a 2000 GTi,, there's a 15 Amp fuse, and a push together connection that powers the MPEM when the engine is not running. My fuse receptacle had that oxidation growth down inside of the contacts, and the push-fit was lightly oxidized. I was not getting the beep beep until I cleaned both. After cleaning I applied dielectric compound to the contact areas before re-connecting. This dielectric compound is nothing more than silicone grease, and is an insulator, but as tightly as the contacts fit, that wasn't a problem. I guess a better way would be to make the connection first, and then apply the grease to keep moisture out. the stuff is great for rubber O-rings too.
About copper wires that oxidize within the insulation.... what makes it start? Saltwater is one way. How it gets so far into the insulation without either end of the effected wire being infected is a mystery to me. Yes, a "megger" would sure be a good thing to use. I remember seeing submersible cable for an oil well being tested with something similar, and I believe it induces a voltage into the conductor being tested, then measures the current loss or voltage drop.
Another possible high resistance connection on Seadoos is the male/female connectors crimped onto the end of the wires. They aren't soldered, just crimped, and are worthy of a visual when troubleshooting electrical issues. Also are the pins on the MPEM connectors, and also on the MPEM, the slots where the fuses plug in.
2000 gti also had stripped threads on the mpem, where the rectifier is fastened to it by way of a very coarse threaded screw. Now I'm not sure it needs to make an electrical connection there, but if not, why would the mpem have lead or whatever it is for this screw to thread into? Seems like plastic would be just fine. I installed my spare mpem that wasn't stripped there, and cleaned all of the ground wires on the Ignition coil, and no more intermittent electrical issues.
 
The engine compression is at 130, the jugs were warped and a couple of member stated that warped jugs could cause the weird problems i am having, so it's just an assessment that my engine's bad base on forum members opinions. I may agree because i took the top end apart and resealed it after having starting issues and the ski ran great for 40 minutes then stopped working again.
If you have even a slightly warped cylinder you will have all kinds of water intrusion issues.
 
2000 gti also had stripped threads on the mpem, where the rectifier is fastened to it by way of a very coarse threaded screw. Now I'm not sure it needs to make an electrical connection there, but if not, why would the mpem have lead or whatever it is for this screw to thread into? Seems like plastic would be just fine. I installed my spare mpem that wasn't stripped there, and cleaned all of the ground wires on the Ignition coil, and no more intermittent electrical issues.

Very interesting observation and about the only thing I didn't check but I wonder what is in there. Sure looks like plastic as you stated.
 
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