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  1. #1

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    possible fuel controller issue

    hi guys

    Im running an R&D fuel controller on a SHO engine in a GPR. recently its lost its top end.. it takes off hard off the line and goes straight to full power (around 7700 RPM) and within a couple seconds the power goes away.. and dwindles back to about 7100 rpm...

    Sounds like a sign of the factory boost cut?


  2. #2
    hitman's Avatar
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    Do you have a boost gauge? If so what kind of boost are you seeing?

  3. #3

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    Quote Originally Posted by hitman View Post
    Do you have a boost gauge? If so what kind of boost are you seeing?
    Hi

    Unfortunatly i dont have a boost guage... i might have to put one on... weve tried fresh plugs, check fuel pressure, and all so far looks ok.. and it runs too well to be a fault with something else. Starts nice, runs smooth.. goes hard off the line then slowly pulls away the rpm and power...

    i was thinking that if the fuel controller is dead ill just get a reflash, though a bit hessitant to throw money at a fuel controller if i have a isue else where... and im a bit stuck as to where to troubleshoot next...

    wish i had my power back

  4. #4
    hitman's Avatar
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    Would also help if I knew the rest of your mods.

  5. #5

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    Hi..

    its a GPRSHO... c3, seadoo style IC (XS style) R&D powershot..

    used to run 82 all day... and its just lost its go... rpms are way down.. though if you go back to idle for a bit and gas it, and it revs up hard and takes off for about 2-3 seconds... then it winds itself back over 2-3 to abotu 7000 rpm and down to abotu 75mph...

    any ideas? Ive changed plugs, new blow off valve (incase was leaking), presure tested the IC... sorta lost now... except for changing the Powershot which i cant find one to borrow..

  6. #6
    mjh3ides's Avatar
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    It sounds like the boost limiter to me. Check the powershot connector on the MAP sensor.

  7. #7

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    it does hey... ill check plugs though it seems wierd... powershot looks to operate OK except for the boostcut.. ill try clean up the plugs and try again

  8. #8
    db2540's Avatar
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    What are your battery volts at high rpm?

  9. #9

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    around 14.2... about 13.9 at idle...

  10. #10

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    Hi guys

    Well ive done some more testing on this issue.. and looks like it may not be boost cut. Ive taken the powershot ouf of the system now and run a R3 reflash... and the issue persists..

    It does feel like the ecu is incrementally closing the butterfly until the engine finally gets to 6900-7000 rpm..

    So since last time.. powershot is out, r3 is in. Taken the intake manifold out to test the butterfly operation, all looks good. Changed blow off valve incase it was leaking, and changed intercooler in case it was leaking.. same same.

    Ive tried a different map sensor, and borrowed a complete pump incase it was prop flexing.... so not in the pump area either

    So the issue is, you gas it off the line, it goes to full rpm and takes off hard, then as you have been on the gas for about 3-5 seconds it slowly pulls revs back to around 7000 and slows the ski to 75mph....

    What other sensors on board would cause this do you think? Im going to test the air intake temp sensor, and the water temp sensor incase it thinks the engine is cold, or the air is really hot... but any other ideas as to what may cause the symptoms?

    The only other info i can give is the engine at one time got a bit rusty, i didnt flush it properly and when the conversion was done the extension pipe on the back of the exhaust was cut so the water that sat in the boot that connects to the waterbox caused condensation and the exhaust valves rusted open... Since then weve cleaned it up and all is OK, and comp tests are 130 each... so all good there.. Maybe the condensation may have affected other sensors that could be contributing?

    Im thinking ill just whack a cable on the butterfly

    Any help would be really appreciated.. i know theres another 10 MPH under this ski and im dying to get it back!!!! last time it went well it ran 83 without the reflash so im dying to see what differences the R3 does....

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