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  1. #1

    Runs rough, black sooty plugs RXP X 2008

    Rough idle, all three plugs are black and sooty. While riding it lacks power and won’t run over 4K rpm. After a minute or so running like this it accelerates to 8k and 70 mph for about a minute then runs rough again. New gas, new DCPR8E plugs, new 42 pound bosh fuel injectors, new CPS, new valves, new valve seals, milled head, rebuilt supercharger, 120 PSI across all three cylinders (+-8.) Timing is accurate, set using both cam and crankshaft pins and checked at least 6 times. Could it be the ECU needs to be reset?

  2. #2
    Picture of new plugs after 20 minutes of riding
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  3. #3
    ptscon's Avatar
    Join Date
    Jul 2013
    That looks like too much fuel.

  4. #4

    Join Date
    Sep 2012
    broken arrow ok
    May have bad map sensor.

  5. #5
    Given the plug design I’m not sure how to test the map voltage. I will order a new sensor, unfortunately it will take about a week to get it. Stand by...

  6. #6
    Thanks to Turboted and nmpeter you were correct it was the map sensor. It would have been nice if there was an error code. This has plagued me for a long time.

  7. #7
    Myself's Avatar
    Join Date
    May 2007
    North Central Arkansas
    Good job guys. I'll forever be amazed at the vast amount of combined knowledge on the various online forums. Usually a day or less and somebody has the correct answer!!

  8. #8

    Join Date
    Sep 2012
    broken arrow ok
    I'm glad you got it fixed.
    Last edited by Turboted; 09-30-2018 at 02:08 PM. Reason: ???

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