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TPS and o2 issues...

Discussion in 'Civic and CRX - EF' started by CasualEF'er, Oct 6, 2016.

  1. CasualEF'er

    CasualEF'er New Member

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    Hey everyone. I've got a 1990 civic hatch with a D15B1 engine, swapped out the 4 speed for the DX 5spd, installed a rebuilt D15B2 head, a J2 header, new timing belt, and a few months back did the MPFI swap with obd2 injectors. (No resister) My pm6 ecu came from eBay, and overall works great. Since the header and MPFI swap though, I have had a TPS code (and replaced it twice, to no avail) and have quadruple checked that it is reading correct voltage (which it is, .5V-4.5V). Also, about 50%-75% throttle, the ecu squeals like crazy (the same way an old tv does when it won't turn on)


    As for the o2 sensor, it too has been replaced twice. Once before the swap, and once after. The J2 header moves the sensor from #2 runner to the collector, so I also tried the common CEL eliminator from BLOX racing, and made no difference.

    If I really step on it and then slow down from around 40-50 with engine braking when it's cold, it will trip into closed loop and run fine. Otherwise, it runs kinda skippy. Especially if the weather is below 65. This thing has really got me stumped...
     
  2. CAFROG

    CAFROG Honda Minion VIP

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    Is it possible to try another PM6 ECU?
     
  3. CasualEF'er

    CasualEF'er New Member

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    I've been wondering that myself. Unfortunately that means buying one because everyone I know with ef's are running p28
     
  4. CAFROG

    CAFROG Honda Minion VIP

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    Might be wise to run a chipped P06 or P28 with your base map (or something very similar) and get a jumper harness. You call some Honda/Acura dismantlers/recyclers and those Si ECU's are out there but, depending on your location, it could be tough.

    The noise you described has never happened to me. Check wiring versus Internet steps for MPFI conversion.

    I know nothing about OBD2 injectors with everything else (ECU mostly) being OBD0. But I'd run Si OBD0 injectors only. Maybe my lack of knowledge? But I'd change them out and wire it all back to OBD0
     
  5. CasualEF'er

    CasualEF'er New Member

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    the difference is that the obd2 injectors are higher resistance so they don't require a resistor. And the ecu has squealed since the day I put it in. All wiring has been checked and re checked and checked again. I know all the electronics on the engine are good as I have tested them all with a meter and all checked out as normal.

    The squealing from the ecu makes me think it has a bad capacitor, as that is what causes most electronics to make any such noise. That would also explain my lack of power below 4200 rpm, and only squealing between 50-75% throttle. I just wanted to see if anyone had any other ideas.
     
  6. CAFROG

    CAFROG Honda Minion VIP

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    As long as you are confident in the wiring, I'd just get another Si ECU. Is there a tuning shop around you? They could be a good way to source another ECU to try (and possibly buy)...but they may be jerks and/or can't get you one to try.
     
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