3D di missfire/low power/limp mode problem solved.

[MYChina]

Hi All

I am new to this forum but thought I would spread the love with a success I just had.

I will start off with my history with this problem. Sorry if it is a bit long but I have had a emotional journey with this ongoing problem.

I am the engineer of a Superyacht with a RXT and a 3Ddi. The RXT has been faultless however my ongoing saga with the 3Ddi's has been a nightmare.
Had a new one on the yacht in 2006. ran fine for the first 10-15 hours then developed an occasional missfire. this then developed into the occasional no power/limp mode sympton. We were doing a trip from Singapore back to the med and I had given it into 5 dealers in variouse countries on the way and all said they could find nothing wrong with it(they never would test ride it as most dealers dont!!!) however apon recieving it back it would run fine for 10-15 min then bog down/limp mode. No matter how many times we had the diagnostic computer on it always had no codes. I had changed the plugs multiple times which seemed to help for a bit but then it would revert back to its old ways!!!
apon getting back to france which is our home base I gave it to the local dealer and said I dont want it back till it is fixed. well they called me a couple of weeks later and said they had gone through everything and ended up stripping the engine down!!. they then informed me that with all the work done and if they reassembled it (still had not found the fault) it would cost the boat almost as much as a new one. so we managed to find a new 2007 model(this was 2010 when we bought it) and I was a happy camper again.
Well guess what!!!! 15 hours into the running it in and jetskii loving guests on board the new one started doing the same thing.F$@K these 3dDI's I am saying!!! Great fun skiis but this is a nightmare problem. So I had organize for the shop to rent us one and take the new one away for repair. they could not pick it up for a couple of days while in the meantime I have some very unhappy guests on board!!!

The Solution !!!!!!

by chance I had cleaned the plugs AGAIN and ran it up. Great on deck but put it in the water and as normal it bogs again. I had read on here maybe and exhaust leak can smother the oxygen in the hull and cause this, so while cruising along I put my hand down to unlatch the cover and BANG!!!! i got multiple High voltage shocks!!!. mmm a lead I think.
So I rip it out of the water and start it up on deck. remove the lid and I could hear it clear the miss. I then proceeded to touch the stainless peg the lid latches onto and BANG!!! a real wopper of a shock.
I removed the storage tray and look at the coil packs and see that they are mounted directly onto a stainless mount that is held in place via the lid locking peg. the top coil pack HT lead is pressed hard onto this stainless mounting plate!!

THE REPAIR

Now if You pull up the rubber cover on the lid latch peg there are two flats that you can get a spanner on. Hold onto the coil pack with one hand and undo the lid lock peg counter clockwise. The coil pack should now come off and you will be able to remove. there are two allen bolts holding the 2 x coil packs to the stainless mounting plate. losen these and carefully inspect the surface of the mounting plate where it sits on the top coil packs HT lead. IF you can see signs of tracking(a spark leaping to places it should not) then I can safely say that this is the cause of all your problems.

now the HT leads are supposedly sealed to the coil pack however obviosly the spark is getting through and it is a bit of a bad design to have the mounting plate so close to the HT lead. these are very high voltage and the spark will track through any week link instead of going to the plugs where it is supposed to hence the missfire/bog

my first attempt was to use liquid tape on the HT lead and a small piece of rubber under the mounting plate(as per pics) and this sorted the problem for 30 mins. on inspection a small amount of water had wetted the area and made a track to the mounting plate at the back where I did not have enough excess rubber overlapping the plate.
my solution was to excessivly coat the HT lead(including lifting up as much of the cap and squirting it in) with silicon/Sikaflex. I then made a thicker rubber plate which was almost twice the area of the mounting plate. then bolted the coilpacks to the mounting plate and applied more silicon/sika between the coil pack and the steel spacers that the bolts run through. I then covered the whole assemble with a ziplock and then replaced.

MK 1 attempt .you can see on the left the rubber does not overhang the plate enough

MK 1 attempt

MK2 and final coating of the HT lead.

I will post more pics if people want them. but the final result was the skii has run like never before and it is now faster than the RXT!!!! Lovely.

On fixing this I asked the dealer that still has our old one in bits if they could check it and low and behold there were tracking marks on the mounting plate of that one as well. All that ball ache for a simple design error.

I hope this is helps and fixes some other peoples problems on here as I see there are quite a few posts with people asking for help for the same problems but no answers. Please let me know what you find and if it fixes your 3Ddi!!!!!!

I have since found that salt water getting into the bilge and touching the starter motor is the main cause of the spark tracking to places it should not, please read posts below about fault finding places of water ingress

:seeya:

 

[1MACGYVER]

Im going to rip mine apart and check for that track mark, ive had an intermittent miss. i really hope thats all it is
Thanks for the info!!

 

[ThreeD]

This is great detective work...Sea-Doo should give you a job fixing their crappy design flaws

 

[bobadoo]

do you think it is same design on 05 800 3d, mine has a horrible low speed miss

 

[Dr Honda]

thanks for the info. I'm sure it will help others. :thumbsup:

 

[crisso]

Great to see you took the time and effort to inform others.This may inspire people to find other problems that are not meant to be there.Thank you.I am now 1 thread closer to helping others

 

[1MACGYVER]

I was hoping this was my problem but as it turns out my coil pack looks quite different

Ive always suspected my injectors needed a clean- for $44 each i had them cleaned, filters changed and flow tested (new injectors here are around $200 each)

Fixed all of my problems- no more running on one cylinder, revs really smoothly, revs higher.
I just took it out for the first run of the season with brand new plugs, its never run so well =) =) =)

 

[Rosaku]

i Would love some more pics and mayby a guid?
Im bad with motor But i seem to be having the same trubbles as you.
I would be super happy if u culd help me out.
Thx

 

[MYChina]

after a winter long of fixing and testing our 3Ddi I have found more to this problem than I first thought.

Are you getting any water in the bilge? if you have the missfire/rough running/limp home after 10min or more of running and have been diving the nose under that water. please remove the rear battery cover and see how much water is in your bilge!!! tip up on an angle if possible as alot of water is stored in the centre of the hull under the fuel tank, so if the hull is level it does not look like alot of water but when tilted back you see all the water that is in the hull. If you have over 2 " of water when the hull is tipped back please read on as I belive this is the problem causing all the symtops of electrical/injection faults.

I have found that our 3Ddi leaks through many places if the nose is dived through waves or under water in a turn. Once the water is about an inch or more deep it touches the starter positive terminal which in turns makes the HT leads arc to everything but the spark plug. I have spent alot of hours going through and finding where all the leaks are that are letting water in. these are

1/ the rubber boot that is "supposed to " seal the wires and steering cable from the handle bars into the main hull. only a loose cable tie from factory. I have sealed inbetween all the wires/cables and in the boot with silicon. I also pulled the handlebars and sealed where the grommet fits the cut out of the hull as water gets past this as well.
2/Screws that hold the elastic for the child polystyrene foot extenders, also at the top of the foot well there are plastic covers that the top of the foot extenders latch into. under these they have drilled 3 holes but only one is used. silicon the other two as an amazing amount of water gets in here.
3/ front tow attachment, pull off ECU mount and pull right hand polystyrene float out of the way. you can see the two nuts that hold on the front tow attach. remove these and pull off tow attachment. fill whole concave with silicon then replace tow attachment.

after doing all the above I cut down my water ingress to a minimum, however when driven hard in turns and diving the nose through waves I have found (via using a waterproof video cam) that water is getting past the air seperator in the top cover and getting sucked into the hull. after some hose testing I have decided to just seal off the front air intakes in the top cover as I believe water is being forced into the top cover through here and overwhelming the air sep with too much water. I still have to do a final test on this mod but the rear openings look more than enough and are in a lot more sheltered place from forced water.

as I said at the start. after mucking around trying to trace ignition faults and injection faults I found it is actually a earthing fault once too much salt water enters the hull which causes missing low power and cutting out. once the hull is sucked out and hosed with fresh water the ski runs fine again untill the water level in the hull rises again.

hope it helps. and I will follow with pics and a test report on the blocking of the front air intakes.

these 3Ddi's are a fantastic concept and are brilliant when running however the build design leaves alot to be desired and you should not have to do this with new a ski. my dealer just said to me where is the water getting in, I said you tell me you are the one that sold me a new skii that leaks. I have since shown them all the places that water is getting in and of course they say well it is out of warranty now so we cant do anything. Wankers these are poor build problems not owner problems.

 

[Rosaku]

Thank you so mutch ! You have helped me loads!
1 problem that i found out is that the guy i got the sea doo 3d di from forgot to tell me that he dident have the storage compartmen.
so when i was riding the water was fludding in ! I took the mac gayver rout ant taiped it up. Now its running like never befor.

 

[MYChina]

yeah our captain had taken that fire extinquisher tray out (because the top cover was too hard to close) and did not tell me, he then took it out and rolled it and filled the hull up above the engine with water. that ski was a right off after that.

Always make sure that storage insert is in otherwise the top cover does not seal properly.

I would still check these other places for leaks as Idealy we want to stop any water from entering the hull. It only gets in if driven under the water in turns or diving the nose. so those people that ride normally might not find any of these problems. Our guests jump off waves and dive the whole ski under the water so I have had to diagnose these problems as our ski takes a hammering.

glad this is helping others. Pics to come in the next two days(when I get off the boat and home to faster net)