Page 1 of 4 123 ... LastLast
Results 1 to 10 of 31
  1. #1

    Yes, it's me again! But with new piece of info...

    Okay, same ski, same problem as in my other 1 or 2 threads that have gone on since early this year .......

    I took a mental break from the ski for a week or two and just today, i decided to try it out in the river again. Figured I'd try it out again before removing or changing more parts based on my other thread with many suggestions/ideas.
    Just as a quick recap for those of you that have gotten familiar with my ongoing symptoms, back in May is when I had it out on the river 3 hours south of Vegas/Lake Mead...thats the day I bought a new MAP sensor from a member and the ski ran KILLER. Back home on the lake, the ski ran like crap again ---> max'n out steady at 7800 rpms and loosing as much as 5mph plus the torque curve sucks. All else being normal with the ski and NO codes.

    reluctantly, i chose to drive it all the way down to the river to try it out (no not 3hrs south, but just 45min on the other side of Hoover dam). As several of you know, I haven't been able to figure out why it ran perfect/normal on just 1 day, on the river....but like crap every time i go to the lake. So, I figured that I'd put "elevation" to the test. Elevation, because thats THE ONLY factor that has currently been singled out as being different between running good and bad.

    I drove it today on the river with the ORIGINAL MAP sensor in it. I swapped between the new one and the old one during my last trip on the LAKE a few weeks ago - with no change between them. Also, no change with the CMD components completely bypassed and not bypassed.
    ***Well, after finding some flat water today, I was able to pull 8050-8100rpms and a best of 79.6mph! Haven't pulled those numbers since my river trip back in May. And 79-80 has been my best speeds since last year, and ^these^ are my normal summer RPMs (winter RPMs are 8100-8150).

    ***SO, my question here in this post is: Is there any sensor (or any device at all) on the 05 RXP that uses/recognizes "elevation" for engine management?? And if so, could this part be faulty? Ive had this ski for 240 hours here in Las Vegas and I've NEVER seen ANY difference with this ski from the lake to the river ever before.....talking about losses of 300rpms and as much as 5mph or more in some cases. It's NOT the weather and it's NOT the river's current.

    ***Lake Mead's elevation - 1100ft
    CO River's elevation below the Dam - 630ish ft.

    That's only about 500ft difference that I'd normally say a normal-running motor wouldn't notice enough to run any different. But, it is running different and this has NEVER happened before in 5 years and 240 hours of owning this ski.

    Thanks to anyone who can help with this new piece of info!! Going crazy here watching summer cruise on by while my ski runs like a dumb ass

  2. #2
    ou812's Avatar
    Join Date
    Jun 2006
    Damn!!! Shallow water maybe? LOL...

  3. #3
    mac_man_luke's Avatar
    Join Date
    Sep 2010
    South Australia
    MAP sensor is what would be affected by elevation because that measures absolute pressure e.g. altitude + boost/vacuum

    Almost sounds like its pig rich or something at altitude.

  4. #4
    Shallow water, Lol Jim this thing is driving me nuts. Unless, as my question there any part that works off of elevation at all....pressure maybe?

  5. #5
    boost junkie skidoochris's Avatar
    Join Date
    Mar 2012
    Davison, Mi
    IMO try the MAT sensor could be acting up it and may be your problem
    Also I see your running only 91 octane with the x charger you may be getting some knock and the ecm is protecting the motor

  6. #6
    The river water is cooler than the lake water? Have you measured the two?

  7. #7
    Unfortunately, 91 is all you'll get out here ....been using 91 in this ski for 240 hours over 5 years.

    Lake and river temps are pretty similar in winter. But yes, in summer the lake warms up and river stays cold. Doesn't matter though, I've had this ski on both waters for 5 years and I ride all year 'round....these temp differences shouldn't, and haven't ever caused me to loose 300rpms and 5mph.

    Thanks for the input...I need all the help I can get at this point. But guys, listen to me when I tell you it's not the weather or water temperature. This is, by far, not a new ski to me and neither are the waters i ride in. Something under the seat is fuk'n up.

    What else can I learn about this MAT sensor?? Where is that one located? I'm also about to replace the air temp sensor on the front of the intake manifold, per someone else's idea.

  8. #8
    Quote Originally Posted by mac_man_luke View Post
    MAP sensor is what would be affected by elevation because that measures absolute pressure e.g. altitude + boost/vacuum

    Almost sounds like its pig rich or something at altitude.
    Is the MAP sensor THE ONLY sensor that could possibly have anything to do with elevation/pressure monitoring?
    It's just weird that my symptom isn't different with a new MAP sensor...only different when on the river vs the lake

  9. #9
    Faulty knock sensor interrupting things maybe??

    Wondering which, or how many sensors would normally crap out at 240hours.
    Meanwhile, wondering which sensors would have come with my new long block from seadoo 160 hours ago? If none of them come with new long blocks, then yes, my sensors etc are all of 240 hours old.

  10. #10
    Orlando Shark's Avatar
    Join Date
    Mar 2009
    Miami, FL
    Elevation has lots to do with boost and pressure. Now add the 91 octane gas which might be making your motor have slight knock.(and regarding this, does the CMD change timing?)

    What afr's are you running?

    To be honest getting around 80 mph at elevation is really good speeds. Only way I see you getting more is adding rpm or boost.

Page 1 of 4 123 ... LastLast

Thread Information

Users Browsing this Thread

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

Posting Permissions

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