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D15b running rich at operating temperature

Discussion in 'General Tech and Maintenance' started by |Chaz|, May 1, 2010.

  1. |Chaz|

    |Chaz| Well-Known Member VIP

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    First off, I'm not throwing any codes. It runs strong until the car comes up to operating temperature, then during acceleration it hesitates and then accelerates slower than it does when it's cold. MPG have decreased significantly. It's not smoking, the exhaust does smell rich of fuel.
    The radiator fan seems like it's taking a little too long to kick on as well, could just be me though, my temperature gauge reads normal. Idles fine, when it's warm it doesn't idle as smoothly as when it's cold but it's still fairly smoothly though.

    I'm running a p08 ECU and a 1-wire o2 sensor.

    Any help would be appreciated, I feel like I'm so close but so far away from being finished with this project.
     
    Last edited: May 1, 2010
  2. phunky.buddha

    phunky.buddha Admin with a big stick Admin VIP

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    New O2 sensor? Intake air temp sensor?
     
  3. |Chaz|

    |Chaz| Well-Known Member VIP

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    Yea I was thinking one of those two problems. It seems like the radiator fan is taking a little too long to kick on... but it could just be me. Could those two issues be related?
     
  4. |Chaz|

    |Chaz| Well-Known Member VIP

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    I'm also not throwing any codes.
     
  5. eg'sforlife

    eg'sforlife New Member

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    When I did this swap I got my motor from hmotors. And I had this problem I traced this to the O2 sensor so I would look into that.
     
  6. |Chaz|

    |Chaz| Well-Known Member VIP

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    What ECU are you running with your swap? Do you currently have a single wire o2 sensor or a 4 wire o2 sensor?
     
  7. eg'sforlife

    eg'sforlife New Member

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    Im running a P91 and 4 wire o2 sensor
     
  8. |Chaz|

    |Chaz| Well-Known Member VIP

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    I got a new o2 sensor and it didn't solve the issue.
     
  9. f22b1 coupe

    f22b1 coupe Junior Member

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    I just replaced a D16Y7 with a D15B and I have to say, I had more problems than you could imagine with fuel, timing, etc. and let me spell it out clearly- unless you have the D15B JDM ECU for it, you need to use EVERYTHING from the D16Y7. I didn't change the Crank sprocket over when I put the crank sensor on and it gave a code, so I'm guessing that's not your problem, but if you are still using the USDM ECU you MUST use the full intake manifold, all sensors, and distributor from the USDM motor. The injectors are different and will flood the piss out of your engine. Also make sure your fuel pressure regulator is functioning properly.
     
  10. 95EGCoupeVtec

    95EGCoupeVtec SOHC VTEC at its best

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    i just finished doing a d15b jdm swap on my brother inlaw's 94 d15b7 dx hatch, we reused his 4 wire o2 sensor, and also used a p28. it runs fine with no lights or anything.
     
  11. |Chaz|

    |Chaz| Well-Known Member VIP

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    It runs fine on a cold day. If it gets hot it acts like the thermostat/radiator fan aren't kicking on. Eventually it throws a code 3 and then goes into limp mode. Not sure what's causing it.
     
  12. Camw336

    Camw336 New Member

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    Check the ground wire
     
  13. K2e2vin

    K2e2vin Senior Member

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    P08, which is what he's using, is the correct ECU for it.

    Definitely check your IAT if you're having issues with different temperatures(I had that issue also btw on my D15B; P28, P06, and P08 had trouble running it when hot).
     
  14. |Chaz|

    |Chaz| Well-Known Member VIP

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    My wires on my MAP sensor actually ended up being backwards.
     
  15. RoughKnight

    RoughKnight Christmas Car

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  16. |Chaz|

    |Chaz| Well-Known Member VIP

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    The position of the wires in the connector were actually different then how they were for my D15b7. Weird huh?
     
  17. RoughKnight

    RoughKnight Christmas Car

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    Ya very, mine was just plug and play :( go turbo like me soon and ripppppp at the track
     
  18. |Chaz|

    |Chaz| Well-Known Member VIP

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    Meh I'd go GSR before I went turbo...
     
  19. RoughKnight

    RoughKnight Christmas Car

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    Turbo d's are alot more fun than n/a b series
     
  20. Magana559

    Magana559 The Warden

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    :moon:
     
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