Injector Cleaning

Discussion in 'General Discussion' started by Dookie, Dec 10, 2009.

  1. 1fastsedan

    1fastsedan Destroyer of Warranties

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    Just to give you some idea Stevo, I had a set of injectors with 5k miles on them serviced at RC Engineering (JonW's shop). I'm having trouble posting the actual print out, but here are the numbers.

    Inj# cc/min before cc/min after
    1 417 421
    2 413 420
    3 411 420
    4 419 422
    5 408 420
    6 410 420
    7 419 422
    8 416 421

    System balance went from 2.7% variance to 0.5%. All spray patterns went from good to excellent.
     
  2. mrjoecool

    mrjoecool way down south

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    hey kyle try some high octane race gas and see if you kr drops or goes away
    then you will know if it is a fuel issue
     
  3. Dookie

    Dookie Foe twenny sics

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    I added in some NOS Octane Boost (racing formula)...I put an entire can into a half a tank. Double what instructions recommend. I drove it a day to get it mixed in well, did a log, and no difference. I know this isn't the same as 105 fuel by any stretch, but i figured it would make SOME difference...it didn't.
    My injectors are from a 10 year old vehicle, and I've run them about 20k miles. They are due for service anyway. I've had this problem ever since I began tracking KR about a year and a half ago, even with previous motor. I chalked it up to piston slap and an exhaust leak on my old motor...My new motor runs like a sewing machine...very quiet and no exhaust leaks from header.
    The only other culprit could be my rear coil-over lower bushings are toast, and I get chatter from them that's very noticeable. Maybe it's conducting through the chassis and the knock sensors are picking it up. I've watched the sensor voltage for each bank, trying to see if it's one side dominant, and it's not...both voltages are pretty equal. When I installed the knock sensors, I torqued them to spec at 15 lb/ft. I've ruled out everything I could...now it's down to the injectors or the bushings. I'll be calling KW to get a bushing set, and sending my injectors to JonW.
     
    Last edited: Dec 11, 2009
  4. srt8-in-largo

    srt8-in-largo Full Access Member

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    Have you tried going back to the stock plugs, or equivalent "R" series from NGK?
     
  5. Dookie

    Dookie Foe twenny sics

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    No, i was actually thinking about going the other way with it and getting another range colder plug, mainly because of my CR. The 2315's i'm running now are 1 step colder from stock, which lots of others are running without any problems...
    I've never "heat ranged" my plugs though, kinda hard to do on the road, easy to do on a dyno. I'll check my plugs for heat range compatibility, and AFR to rule it out.

    Another thing i did test out was to pedal the car up gradually but quickly to WOT versus slamming the pedal...same result.
     
    Last edited: Dec 13, 2009
  6. Dookie

    Dookie Foe twenny sics

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    I did a plug read...plugs are too hot, i think i've found my problem. Their isn't any color change to the ground strap at all. The strap is a greyish color, it's a little darker at the base where it attaches. Looks lean as well. My AFR on wide band is saying bounces around 13.0 at first hit then richens to 12.4.

    What are my choices for plugs? NGK 5107 or 6510 the best options?
     
    Last edited: Dec 14, 2009