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2G Test fuel pump/mfi relay

Posted by JGeezyyy, Jan 12, 2019

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  1. JGeezyyy

    JGeezyyy Proven Member

    44
    1
    Joined Feb 2, 2015
    Naugatuck, Connecticut
    Diagnosing a no-start. Fuel pump isn’t turning on. Tested the fuel pump by directly connecting power to it and it turned on. Trying to test the relays. In the picture below it’s sayingto test the continuity between 2-4. Do i have them labeled correctly in the pictures? And this is just with the multimeter correct? I’m not good with this kind of stuff. I connected the black end of the meter to “3” and the red to “4” as I have in the pics. On the left terminal it’s only showing 1.xx. The terminal on the right isn’t showing anything for a reading. I know it’s supposed to be 70 if done correctly but I just want to make sure I’m testing it correctly so I can rule it out.
     

    Attached Files:

    232  2

    1997 Mitsubishi Eclipse GSX
    awd · manual · 2G DSM
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  2. steve

    steve DSM Wiseman

    12,641
    464
    Joined Feb 3, 2002
    Boulder, Colorado
    The manual usually shows pin numbering looking from the top (where the wires go in) of a connector. So I think you have them labeled incorrectly. You are measuring the relay and not the harness, correct?
     

    3K  0

    1991 Mitsubishi Eclipse GSX
    manual · 1G DSM
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  3. pauleyman

    pauleyman DSM Wiseman

    4,985
    897
    Joined Nov 19, 2011
    oklahoma city, Oklahoma
    Very easy to just jump the test connector on the firewall. Might help rule out relay
     

    Street Build 2K  1

    1997 Eagle Talon TSi AWD
    awd · manual · 2G DSM
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  4. JGeezyyy

    JGeezyyy Proven Member

    44
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    Joined Feb 2, 2015
    Naugatuck, Connecticut
    Sorry for the labeling I should have labeled the relay.

    At first I’ll admit I was testing the harness. But I’ve been testing the relays out of the car for the past day or 2 and can’t get the multimeter to give a solid reading. It’ll flash a random number, sometimes 30, sometimes 90, then drop back down to 0.

    I’ve been testing them per the manual in the picture. Am i testing it wrong?

    On 2gs is it the black or blue connector? I’ve been getting mixed answers. When I tried this last week nothing happened on either connector so again I wasn’t sure if I was properly testing.
     
    Last edited by a moderator: Jan 14, 2019

    232  2

    1997 Mitsubishi Eclipse GSX
    awd · manual · 2G DSM
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  5. steve

    steve DSM Wiseman

    12,641
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    Joined Feb 3, 2002
    Boulder, Colorado
    There are two parts to the relay, the coil and the contacts.

    The coil will have a fixed resistance between it's two connectors (pins 2 and 4).

    It's the coil that gets battery voltage fed to it which creates an electromagnet that cause the contacts to connect. When there is no voltage across the coil, the contacts are not connected (Infinite ohms between pins 1 and 3) and when there is voltage across the coil, the the contacts are connected (0 ohms between pins 1 and 3)

    Looking down into the relay with the ridge that the connectors snaps on facing away from you the pins are:

    1 2
    3 4

    On the 2g's that use these two relays rather than the old MPI relay both relays are the same, one's for the car MPI circuit and the other for the fuel pump.
     

    3K  0

    1991 Mitsubishi Eclipse GSX
    manual · 1G DSM
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  6. JGeezyyy

    JGeezyyy Proven Member

    44
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    Joined Feb 2, 2015
    Naugatuck, Connecticut
    Okay so I think I’ve been testing correctly then. The way I have it in the picture is the correct orientation if I’m not mistaken?
     

    Attached Files:

    232  2

    1997 Mitsubishi Eclipse GSX
    awd · manual · 2G DSM
    Loading...
  7. steve

    steve DSM Wiseman

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    Boulder, Colorado
    Your holding them the way I'd expect. The right top and bottom pins should measure about 70 ohms between them. What do yours measure?
     

    3K  0

    1991 Mitsubishi Eclipse GSX
    manual · 1G DSM
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  8. JGeezyyy

    JGeezyyy Proven Member

    44
    1
    Joined Feb 2, 2015
    Naugatuck, Connecticut
    I have the red on pin 4 (bottom right) and the black on pin 3 (top right). When I try to test the ohms on one and 3 it’s always a different number, sometimes 30, sometimes 90. But it always goes back to 0 if I keep the test leads on.
     

    Attached Files:

    232  2

    1997 Mitsubishi Eclipse GSX
    awd · manual · 2G DSM
    Loading...
  9. JGeezyyy

    JGeezyyy Proven Member

    44
    1
    Joined Feb 2, 2015
    Naugatuck, Connecticut
    So I just noticed. I’ve been testing 1 and 3 instead of on 2 and 4 while testing. They are both around 71 and 72 ohms.
     

    232  2

    1997 Mitsubishi Eclipse GSX
    awd · manual · 2G DSM
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  10. JGeezyyy

    JGeezyyy Proven Member

    44
    1
    Joined Feb 2, 2015
    Naugatuck, Connecticut
    My only question now would be where would I test now? If the fuel pump turns on outside of the car and the relays are good?
     

    232  2

    1997 Mitsubishi Eclipse GSX
    awd · manual · 2G DSM
    Loading...
  11. steve

    steve DSM Wiseman

    12,641
    464
    Joined Feb 3, 2002
    Boulder, Colorado
    The next test as shown in the FSM is to apply battery voltage to 2 and 4 and see if 1 and 3 switch.

    I don't have access in the mountains to my FSM so I can't say what color wire the Fuel Check Connector under the hood is. But to use it you apply +12v to it and the pump should run.

    However that test bypasses the ECU and fuel pump relay operation, it's just feeding 12v to the same place after the FP relay.

    Without DSMLink it's difficult to get the ECU to force the fuel pump on. You can check to see if by grounding the FP relay pin at the ECU that the relay activates and runs the pump which leaves the ECU as the last unknown.
     

    3K  0

    1991 Mitsubishi Eclipse GSX
    manual · 1G DSM
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  12. JGeezyyy

    JGeezyyy Proven Member

    44
    1
    Joined Feb 2, 2015
    Naugatuck, Connecticut
    When 2 and 4 are getting power, do I test ohms on 1 and 3? If so, it flashes random numbers but eventually go down to 0. I have dsmlink, but I can’t get my cable to connect anymore. Also, when I tried the check connector last week, nothing happened. So it’s confusing me :banghead:. My check engine light did come on with the key turned to on as it’s supposed to, then turned off. So no clue why the cables not working. I even sent it in to ECMlink and they said the cable was fine. Just received it back the other day actually. I have a video of the car trying to start last week but can’t seem to figure out how to upload it. (Stupid iPhones LOL)
     

    232  2

    1997 Mitsubishi Eclipse GSX
    awd · manual · 2G DSM
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  13. GST-RIDER 95

    GST-RIDER 95 Proven Member

    32
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    Joined Jul 22, 2004
    Inland Empire, California
    I’m helping my cousin fire up his 97 GST.
    After a head job and wire harness tuck, the fuel pump doesn’t get power. Cranks over has spark and no fuel.
    Crank position sensor, trigger plate, plug wires and fuel filter are brand new.
    Coil pack & igniter, MPI relays, CPS, Engine fuse, fuel pump and coolant temperature sensor either have continuity, power or ohm tolerances on point.
    I stumbled on the following thread.
    http://www.orldsm.com/archive/index.php/t-12221.html
    And will definitely start tracing ground from the fuel pump to beyond the firewall.
    I’ll probably do this on Thursday night.
    The only plug on the harness I didn’t get any power or any type of reading was the triangle coil pack one.
     
  14. JGeezyyy

    JGeezyyy Proven Member

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    Joined Feb 2, 2015
    Naugatuck, Connecticut
    I found a local guy who’s gonna let me use one of his spare ecus to see if that is the issue since I also can’t connect to dsmlink. Hopefully that’s my issue. If not I’m gonna have to chase the fuel pump wiring to make sure it’s all good.
     

    232  2

    1997 Mitsubishi Eclipse GSX
    awd · manual · 2G DSM
    Loading...
    GST-RIDER 95 likes this.
  15. chrysler kid

    chrysler kid Proven Member

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    Mckinney, Texas
    It's the black connector on the firewall

    2g only sends power to fuel pump when key is at start position unless you jump the connector on the firewall

    The pgmfi relay controls more than the fuel pump, you could always just make your own fuel pump hotwire kit with a seperate relay like the do on a hotwire kit
     

    1K  15

    1998 Mitsubishi Eclipse GST
    fwd · automatic · 2G DSM

    2K  12

    1996 Mitsubishi Eclipse GST
    fwd · manual · 2G DSM

    1K  0

    1996 Mitsubishi Eclipse GST
    14.1 @ 97 · 2G DSM
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  16. GST-RIDER 95

    GST-RIDER 95 Proven Member

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    Joined Jul 22, 2004
    Inland Empire, California
    You’ve inspired me. One of the clerks at our San Bernardino 40th street Autozone has a 97 as well. I’m tempted to ask him to let me connect our ECU in his car, just to rule out a bad control unit as well.
     
    JGeezyyy likes this.
  17. GST-RIDER 95

    GST-RIDER 95 Proven Member

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    Joined Jul 22, 2004
    Inland Empire, California
    When you do jump this black test wire,

    is it safe to crank the engine to see if it will fire up, or is this test connector only intended to just rule out bad EFI and pump?
     
  18. dustyboner

    dustyboner Proven Member

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    Joined Mar 13, 2016
    abq, New Mexico
    on these relays, the silver pins are for the trigger (coil) and the copper pins are for the load

    image-jpg.jpg
     
    steve likes this.
  19. luv2rallye

    luv2rallye DSM Wiseman

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    Minneapolis, Minnesota
    JGeezyyy: You do know, right, that on a 2g turbo (but not 2g NT) the fuel pump is only powered when the engine is turning getting CAS pulses (like cranking or running). With engine not turning and key in "ON" position, the fuel pump does not get power.
     

    2K  0

    1999 Mitsubishi Eclipse GST
    14.200 @ 95.000 · 2G DSM
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    steve and GST-RIDER 95 like this.
  20. JGeezyyy

    JGeezyyy Proven Member

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    Joined Feb 2, 2015
    Naugatuck, Connecticut
    Yes I have read that, it wasn’t turning on while I was cranking.
     

    232  2

    1997 Mitsubishi Eclipse GSX
    awd · manual · 2G DSM
    Loading...
  21. GST-RIDER 95

    GST-RIDER 95 Proven Member

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    Joined Jul 22, 2004
    Inland Empire, California
    After reading this response I remembered reading the following awnswer from Tuff4x4 on cargurus.
    https://www.cargurus.com/Cars/Discussion-t8186_ds573815
    What is the relay module he is talking about?
    Also, how does the ignition coil’s harness tie in with the MFI and the relay module in correlation with fuel pump power.
     
  22. 311oneG

    311oneG Supporting Member

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    Joined Dec 14, 2018
    Spanish Fork, Utah
    So to correctly check the relays, do you need to crank (turn key to start) to get an accurate reading?
     

    Street Build 246  1

    1990 Mitsubishi Eclipse GST
    fwd · manual · 1G DSM
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  23. JGeezyyy

    JGeezyyy Proven Member

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    Joined Feb 2, 2015
    Naugatuck, Connecticut
    I don’t think so. I was able to get a reading by connecting power to pin 2 and 4 ( in the picture above ) while they are connected you test the ohmswith a multimeter, should be around 70
     

    232  2

    1997 Mitsubishi Eclipse GSX
    awd · manual · 2G DSM
    Loading...
  24. chrysler kid

    chrysler kid Proven Member

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    Joined Dec 20, 2002
    Mckinney, Texas
    How do you know the fuel pump isnt working.
     

    1K  15

    1998 Mitsubishi Eclipse GST
    fwd · automatic · 2G DSM

    2K  12

    1996 Mitsubishi Eclipse GST
    fwd · manual · 2G DSM

    1K  0

    1996 Mitsubishi Eclipse GST
    14.1 @ 97 · 2G DSM
    Loading...
  25. JGeezyyy

    JGeezyyy Proven Member

    44
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    Joined Feb 2, 2015
    Naugatuck, Connecticut
    I don’t hear the whining when trying to crank. No click at the gas cap. I even tried starting it while the back seats removed to make sure I’d hear it.
     

    232  2

    1997 Mitsubishi Eclipse GSX
    awd · manual · 2G DSM
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