2003 RXDI fuel/air issues! please help me!

[jhare86]

Hi guys! Im new to this site and this is my first thread, if being a premium member will help me diagnose better i will sign up in a heart beat! ok, this is my issue: 03 RXDI. It doesnt get up to over 8 miles a hour in the water. The plugs are telling me something.. The mag cylinder seems to be making all the power. Heres a list of everything ive checked out, and changed. First off- the pto cyl, plug is coming out very black everytime. Black! Not tan, or even close. The mag cyl plug is coming out white! not even tan but looks like brand new white. it will rev out to 7000 rpms out of the water. When you put it in the water it wont rev over about 3200. It seems the mag cyl is the only one making power off idle. If, while i am running it in the water and pull the pto cyl plug wire the mag cyl will keep the engine running at idle by itself. Then if i do just the opposite with the pto cly..it sort of sputters then stalls out, and wont keep the engine running by itself. Also, with just the rear cyl plug wire hooked up out of the water on the trailor (pto cyl) it will barly idle, touch the throttle and it doesn die, but will NOT gain any rpms at all. chokes out... Do exactly the same thing but with the mag cyl while the rear is disconnected from the plug wire. It will gain rpms slowly... But it will rev on just the lead cyl. Ehhhhh im suprised i Havnt pulled all my hair out yet. And i have spent a few hours reading threads and posts of other people with the same ski, similar problems. here is a list of things i have checked out. i have tested the comp, both cyl are exactly the same at about 125psi. I have replaced the fuel pressure regular. I have checked both the fuel pump pressure AND i installed a t in the air line with clamps and a air pressure gage in line, thats pumping about 78-80 psi according to my gage. Drained all the fuel and put new fuel in, 92 oct. Also, we have the exact same year and model also of another ski... So i didnt want to waste more money so i took the air pressure reg out of the other one and put it in this ski to test it... None of anything i mentioned above has made a difference. (note: the other ski is running great) so i got frustrated and then swapped out the entire fuel rail with everything on it still, with the good running ski. Still have the same problem... Rear cylinder dies out off idle after everything i just mentioned. Am i doomed!?? please help me i so so much appreciate it

 

[jhare86]

Hi guys! Im new to this site and this is my first thread, if being a premium member will help me diagnose better i will sign up in a heart beat! ok, this is my issue: 03 RXDI. It doesnt get up to over 8 miles a hour in the water. The plugs are telling me something.. The mag cylinder seems to be making all the power. Heres a list of everything ive checked out, and changed. First off- the pto cyl, plug is coming out very black everytime. Black! Not tan, or even close. The mag cyl plug is coming out white! not even tan but looks like brand new white. it will rev out to 7000 rpms out of the water. When you put it in the water it wont rev over about 3200. It seems the mag cyl is the only one making power off idle. If, while i am running it in the water and pull the pto cyl plug wire the mag cyl will keep the engine running at idle by itself. Then if i do just the opposite with the pto cly..it sort of sputters then stalls out, and wont keep the engine running by itself. Also, with just the rear cyl plug wire hooked up out of the water on the trailor (pto cyl) it will barly idle, touch the throttle and it doesn die, but will NOT gain any rpms at all. chokes out... Do exactly the same thing but with the mag cyl while the rear is disconnected from the plug wire. It will gain rpms slowly... But it will rev on just the lead cyl. Ehhhhh im suprised i Havnt pulled all my hair out yet. And i have spent a few hours reading threads and posts of other people with the same ski, similar problems. here is a list of things i have checked out. i have tested the comp, both cyl are exactly the same at about 125psi. I have replaced the fuel pressure regular. I have checked both the fuel pump pressure AND i installed a t in the air line with clamps and a air pressure gage in line, thats pumping about 78-80 psi according to my gage. Drained all the fuel and put new fuel in, 92 oct. Also, we have the exact same year and model also of another ski... So i didnt want to waste more money so i took the air pressure reg out of the other one and put it in this ski to test it... None of anything i mentioned above has made a difference. (note: the other ski is running great) so i got frustrated and then swapped out the entire fuel rail with everything on it still, with the good running ski. Still have the same problem... Rear cylinder dies out off idle after everything i just mentioned. Am i doomed!?? please help me
i so so much appreciate it

does anyone know who i should talk to about this? Thanks

 

[Dr Honda]

First... Welcome.

Second... you got to give it more than a couple hours to get an answer.


ANyway... a Di engine only idles on one jug. So... what you are seeing there is right.

To start you need to get us 3 things

1) Engine compression
2) Fuel pressure
3) Air pressure.


Get that, and we will go from there.

 

[jhare86]

Hi guys! Im new to this site and this is my first thread, if being a premium member will help me diagnose better i will sign up in a heart beat! ok, this is my issue: 03 RXDI. It doesnt get up to over 8 miles a hour in the water. The plugs are telling me something.. The mag cylinder seems to be making all the power. Heres a list of everything ive checked out, and changed. First off- the pto cyl, plug is coming out very black everytime. Black! Not tan, or even close. The mag cyl plug is coming out white! not even tan but looks like brand new white. it will rev out to 7000 rpms out of the water. When you put it in the water it wont rev over about 3200. It seems the mag cyl is the only one making power off idle. If, while i am running it in the water and pull the pto cyl plug wire the mag cyl will keep the engine running at idle by itself. Then if i do just the opposite with the pto cly..it sort of sputters then stalls out, and wont keep the engine running by itself. Also, with just the rear cyl plug wire hooked up out of the water on the trailor (pto cyl) it will barly idle, touch the throttle and it doesn die, but will NOT gain any rpms at all. chokes out... Do exactly the same thing but with the mag cyl while the rear is disconnected from the plug wire. It will gain rpms slowly... But it will rev on just the lead cyl. Ehhhhh im suprised i Havnt pulled all my hair out yet. And i have spent a few hours reading threads and posts of other people with the same ski, similar problems. here is a list of things i have checked out. i have tested the comp, both cyl are exactly the same at about 125psi. I have replaced the fuel pressure regular. I have checked both the fuel pump pressure AND i installed a t in the air line with clamps and a air pressure gage in line, thats pumping about 78-80 psi according to my gage. Drained all the fuel and put new fuel in, 92 oct. Also, we have the exact same year and model also of another ski... So i didnt want to waste more money so i took the air pressure reg out of the other one and put it in this ski to test it... None of anything i mentioned above has made a difference. (note: the other ski is running great) so i got frustrated and then swapped out the entire fuel rail with everything on it still, with the good running ski. Still have the same problem... Rear cylinder dies out off idle after everything i just mentioned. Am i doomed!?? please help me
i so so much appreciate it

does anyone know who i should talk to about this? Thanks

 

[jhare86]

hi not Shur what i did but i didnt mean to post that twice? Must be these phones! anyway thank you. here is your answers.
Mag cyl comp- right about 131psi
pto cyl comp- right about 135psi

its kind of hard to see the exact air pressure when its running cause my needle jumps around just a ta.. But when its at idle the pressure looks right about 77 psi at idle. And taps out wide open just touching 80. As for the fuel pressure we used a auto mobile gage that tapped out at 100 on the reading, as we ran it the needle itself was buried past the hundred mark by at least the distance of a 5 psi mark. We did have the dealership test it also and they said it was in spec. So i take it its very close to 107. Something i didnt mention before is i took off the air Injectors and fuel Injectors and brought them to a guy in town here who flow benched them all and put them in a sonik cleaning tank. So... From his results on the bench they seemed to be working fine. With the air Injectors putting out 690 cc's both. And the fuel Injectors doing 85 cc's both. Also i swapped the air Injectors even after i got them back just to see if my problem switched cyl on me after i did that, just for the idea, that guy doesnt have them under any sort of load while doing his tests. Either way it didnt make a difference you wouldnt think it could be that complicated...air,fuel,compression. Is there only one t.p.s or two? thanks for your reply

 

[jhare86]

now i switched out the pto cly t.p.s and the intake tempature sensor with the good ski. Also switched out the cdi unit. No luck

 

[Jonnyivy]

Hey bud,.. I spent weeks trying to figure out what was wrong with mine (same basics as yours) ,... got fed up doing what your doing now and just sent it off to the jetski garage,.. still waiting for the diagnostic results. I have a strong feeling the TPS's are needing zero'd and calibrated.

Jonny

 

[jhare86]

yours is doing the same sort thing as mine?! Wow. Well, at least this isnt the only one. It seems ive looked at what i think is everything that controls almost everything with that cyl.. Im stumped. I think you might be right about the tps needing calibrated. But when i swapped the two out with the good running ski the problem didnt seem to get any worse or any better.. Keep me posted on your results.. When are you expecting them? thanks for letting me know i appreciate it lots

 

[jhare86]

yours is doing the same sort thing as mine?! Wow. Well, at least this isnt the only one. It seems ive looked at what i think is everything that controls almost everything with that cyl.. Im stumped. I think you might be right about the tps needing calibrated. But when i swapped the two out with the good running ski the problem didnt seem to get any worse or any better.. Keep me posted on your results.. When are you expecting them? thanks for letting me know i appreciate it lots

 

[Jonnyivy]

I had all parts on mine off, inspected/ tested and could not find the cause. Replaced the MPEM as it wasn't sending electrical current to the Mag side top injector. The new one does now but it still won't revout properly. I presumed that the TPS were needing reset to mate up with the new MPEM (as I was told on forums). There could be 100 differant other probable causes, but in the end I just booked it in to the local Jetski centre. The waiting list is around 7-10 days so should get a phone call next week,... hopefully with some good news that it doesn't need a hefty cheque to put it right !!!

 

[jhare86]

yea no doubt... Ill say i probably have 5-7 hours playing around with this thing. Hate giving up butwhenyou dont have access to the
buds system makes it tuffer to diagnois.please keep me updated when you get some results back that would be just great !

 

[jhare86]

hey bud! did you ever get to figure out what was causing your ski to run so weird??? thanks looking forward your reply

 

[96spxpos]

did you ever find out yours jhare?

 

[jhare86]

no i didint have enough room to have it in my shop for months... But i will prob start working on it again soon, so im starting to pick around for info with people that are having similar problems before i have it again at my shop

 

[DooWacka]

A couple of things that I didn't see you mention trying yet.
Measure battery voltage while running, it should be 13v+.
The DIs (MPEM) act up in a variety of ways when not getting enough volts.
Also, since you have an identical unit, you should try swapping in the "good" MPEM, and using the key that goes with it. Even though it isn't perfectly set up for the TPS and other settings, it would still run much better if the MPEM is the problem.
I just see that you've spent a lot of effort on the fuel/air rail, and nothing in other areas, like voltage, spark, and MPEM.

 

[96spxpos]

fyi, i had the same issue with mine..revved awesome out of the water,wouldnt even plane up in the water..changed plug boots n cut wires back a 1/4 inch before putting them into the new(used) boots..ran like a top...try it.cheap, easy inexpensive..if u dont have a new or other used set of boots, just do the wire cuts and see if that helps..kinda have a feeling it will

 

[Jonnyivy]

okay,...its all sorted now,.. got the ski running superb, had in the sea a couple of weeks ago and it ran great,.. first time owning and riding a ski and its awesom !! Turned out that it was a bent tooth on the CPS pick-up ring inside the mag cover. How it got bent I do not know,.. maybe while it was diss-assembled ?. Anyway, I straightened it out and set it with the others using a set of feeler guages. What a time was spent looking all around the engine for other probable faults. My advise to anyone searching for a cure especially on the Di model is take it to a dealer and get it on the BUDS diagnostic machine to pin-point the cause.
Happy days ahead !!

Jonny