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ecu problem

Discussion in 'ECU's, Electronics, and Tuning' started by bigodub, Jan 27, 2008.

  1. bigodub

    bigodub New Member

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    car: 91 hatch obd-1 conv.
    motor: d16z6

    i have a chipped p28 that i bought from 1320 and i used it for 2 days drove about 20 miles and when i went to start it on the 3rd day there was no prime from the fuel pump. but weird multiple clicks from the main relay. i did the main relay test it was good and i did the main relay harness test and that also tested good. i switched out ecus and the other ones work fine but this p28 does not. can this be fixed, and if so how?
     
  2. YBLEGAL

    YBLEGAL Regular Member w/ Cheese

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    it's proabably the fuel pump relay

    i would suspect you can run that to some sort of voltage to cause the fuel pump to turn on anyway. just put it on a toggle switch. but still the ecu would throw a code. idk, see if you can pull codes. who knows what all is wrong with it
     
  3. bigodub

    bigodub New Member

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    if it was the fuel pump relay wouldnt it not work for all ecus
     
  4. YBLEGAL

    YBLEGAL Regular Member w/ Cheese

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    no the fuel pump relay is inside the main relay and is triggered by the (usually) green/yellow wire from the ecu
     
  5. bigodub

    bigodub New Member

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    i just bought the main rely like 2 weeks ago it tested good yesterday.both relys worked and i went thru the whole test pattern.
     
  6. YBLEGAL

    YBLEGAL Regular Member w/ Cheese

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    no no. not the relay. a relay needs device power, device output, signal power, and signal ground.

    the ecu sends a signal to the main relay telling it to give power to the fuel pump. the main relay is the one that gives power to the fuel pump. the ecu tells the main relay.

    got it?
     
  7. bigodub

    bigodub New Member

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    ok so the ecu sends 1 signal to the main relay. so if the main relay harness test comes out ok then i must not be getting a signal from the ecu. how can i remedy that problem without buying a new ecu.
     
  8. YBLEGAL

    YBLEGAL Regular Member w/ Cheese

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    sorry i cant go start my car, i'm doing a wire tuck right now, but to be 100% safe in this, i'd like you to find any honda, and check the voltage between the green/yellow wire (should be, hopefully) and ground.

    then let me know what voltage it is and i'll tell you what wire to splice the green/yellow into on yours. i could tell you why, but i'll keep it simple. can you do that?
     
  9. bigodub

    bigodub New Member

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    yes. ill do it in the mourning
     
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