Fuel pump relay is doing a fast double-click

Discussion in 'The Garage' started by AustinJake, Feb 20, 2013.

  1. AustinJake

    AustinJake TE450-KLE-FXDWG

    Joined:
    Aug 20, 2010
    Oddometer:
    3,913
    Location:
    Austin, TX
    2010 Husky TE450

    Fuel pump relay clicks on and off within a quarter second. It's supposed to click on...prime the injector 3 secs...click off.

    Battery is strong, 12.8v standing, no decrease when key is switched on.

    Fuel pump is fine, I put 12v to it and it spins freely.

    Relay is actually burping the fuel pump with the micro-burst of 12v, when it clicks on for a quarter second and then off.

    All 3 relays on the bike are doing the same thing. Hard to believe 3 relays all go bad over the span of 3 days.

    All grounds are good, unchanged from when the bike ran 3 days ago.

    None of the 4 wires going into the relay are grounded. All fuses are good.

    The relay double-clicks fast with the fuel pump hooked up to it or not.

    Dash shows a FAIL message, no codes, but the system sees something wrong.
    #1
  2. AustinJake

    AustinJake TE450-KLE-FXDWG

    Joined:
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    3,913
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    Austin, TX
    Can anyone confirm that it is the ECU that is controlling the 3 second fuel pump priming when the key is first turned on. The relay is not smart enough for that step correct?


    UPDATE
    Even though I am pretty sure it's not the relay, I will attempt to find one of these at the auto store this morning
    [​IMG]
    #2
  3. a1fa

    a1fa Throttle Jockey™

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    I dont know about TE450, but my G450X will actuate fuel pump for couple of seconds if you bump the ignition. My microsquirt car also does the same thing... it primes the fuel lines.
    #3
  4. a1fa

    a1fa Throttle Jockey™

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  5. AustinJake

    AustinJake TE450-KLE-FXDWG

    Joined:
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    I started focusing in on what devices or wires would cause the ECU to shut off the fuel pump, like the kill button, the tilt sensor, wires bare to the injector, or....the fuel pump! Problem was at the 2 connectors to the aftermarket fuel pump I run, so yeah, the connectors are my work, I only wrapped the positive with some wire wrap, and left the negative bare, well, 2 years and 12,500 miles of vibrations wore thru the wrap on the positive connector and suddenly, right after I finish a head gasket replacement, the positive and negative connectors at the fuel pump decide to start touching! I re-wrapped BOTH of them and the fuel pump spun right up, 2-3 seconds of rapturous priming sound! Electrics, I suck at....

    [​IMG]
    #5
  6. P 0 P E Y E

    P 0 P E Y E Bald rider

    Joined:
    Nov 13, 2008
    Oddometer:
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    Location:
    southern Connecticut U S A
    For future reference, chattering solenoide or relay indicates lower than normal voltage to the part.

    In your case it was a loose connection.
    #6