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Weird electrical problem

Discussion in 'Non-Turbo Tech questions' started by yellowpony, Jan 2, 2011.

  1. yellowpony

    Joined:
    Dec 14, 2007
    I am wiring in my new hp efi system, and for some reason, when I turn the key to run, it does not prime the pump. It is set to prime for 3 seconds. The problem is, when I go to shut the power off, the pump turns ON! Is this an issue of a bad relay? It is the same relay that I had with the xfi, and it worked fine, but has been a few months since I went to use it. I am not very good with electrical gremlins, can anyone shed some light on this? Bad relay?

    Anthony
     
    yellowpony, Jan 2, 2011
    #1

  2. 1sicpny

    Joined:
    Feb 16, 2005
    how is the battery, this would happen on my old fast system when the battery was down.
     
    1sicpny, Jan 2, 2011
    #2

  3. yellowpony

    Joined:
    Dec 14, 2007
    You know, of all the stuff I checked, I didnt check that! Good call man! I will do that!

    Anthony
     
    yellowpony, Jan 2, 2011
    #3

  4. Nosman

    Joined:
    Mar 8, 2005
    Is the relay a 4 prong or 5? If it's a 5, you may have the pump connected to 87A instead of 87, and 87A is a normally closed contact I believe.
     
    Nosman, Jan 2, 2011
    #4

  5. 1sicpny

    Joined:
    Feb 16, 2005
    Hey Anthony another issue I had when I first did my fast
    system. Where I had my 12 volt switch power it would lose volts
    when I turn the key on. This also caused the same problem.
     
    1sicpny, Jan 3, 2011
    #5

  6. yellowpony

    Joined:
    Dec 14, 2007
    Nosman, I believe it is a 5 prong, I have no wires going to the middle of the relay. The hp uses a 12v signal to power the relay. They state that if the pumps draws higher than 12a to up the gauge wire and use an additional relay to power the pump, which i have done. The ecu has a built in relay, but my pump pulls 14a at 45psi. I am thinking of just bypassing the ecu and using my switch panel to turn the pump on/off with a relay. I will give your guys ideas a shot and see what happens. My 12v switched source is verified, its hot cranking, so I don't know what else could be wrong, but will give your ideas a try! Thanks guys!

    Anthony
     
    yellowpony, Jan 3, 2011
    #6

  7. yellowpony

    Joined:
    Dec 14, 2007
    yellowpony, Jan 3, 2011
    #7

  8. yellowpony

    Joined:
    Dec 14, 2007
    Talked with Dennis at moore racecraft. He knows his shit about these holley setups, turns out the holley supplies a 12v signal for the fuel pump, where the fast boxes supply the ground. I didnt have the relay grounded because of this. I grounded the relay to the batter and ran a 12v to the relay, and the 12v from the ecu, and voila, it works. Thanks for the tips guys!

    Anthony
     
    yellowpony, Jan 3, 2011
    #8

  9. 1sicpny

    Joined:
    Feb 16, 2005
    awesome
     
    1sicpny, Jan 3, 2011
    #9
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