Announcement

Collapse
No announcement yet.

M50TU won't start (Fixed, starts every time)

Collapse
X
Collapse
 
  • Page of 1
  • Filter
  • Time
  • Show
Clear All
new posts
Previous template Next
    #1

    M50TU won't start (Fixed, starts every time)

    So everything is in and from everything I can see it is in correctly. Turn key, cranks and cranks, but red 413 DME is not telling injectors or spark plugs to fire.

    So... I checked the crank sensor ohms at the DME connector (88 pin female type that plugs into DME, pins 16/43) and I got 530 ohms, well within spec.

    So... I did the stomp test and i get a mysterious single blink. From searching, code 1000 signifies the end of the code sequence. At this point i clear all stored codes and re-try the stomp test, code 1444 is flashed. All clear. Try starting her again and get 1000 after trying the stomp test again. I'm wondering why it shows 1444 before cranking and 1000 after. Weird?

    Also, pin 1 & 38 of the ecu are supposed to ground the BR/GN wire to the fuel pump & O2 sensor relays, respectively. This isn't happening. I have the fuel pump relay removed and a jumper wire in it's place to provide pressure.

    Confirmed fuel pressure (loosened clamp at filter a couple turns and started pouring out), lack of ticking fuel injectors or fuel smell, and no observed spark with coil and plug resting on valve cover. All make me think that the CPS is bad. However, as I stated it's reading within spec.

    All grounds at the DME connector have been checked (good) and I tried swapping in a different red 413 DME (no change). The IAC is buzzing and i'm getting an audible click on the main/DME relay.

    Please help. Why is my DME getting power, but not firing the injectors, plugs, or fuel/O2 relays? Bad harness?
    Last edited by EürOV3R; 08-18-2012, 05:01 PM.
    Tags: None
    #2
    just cause it ohms out fine doesnt mean it is fine.

    Check Us out on Facebook
    Needing a harness adapter or wiring help? Check it out: also have 24v motor mounts, E30 M3 covers and E36 ECU mounts!
    Full Product Line Tuning
    OBD2 Tuning Available! OBD2 E36, S54 Swap, S62 Swap, etc: tuning@MarkertMotorWorks.com Dyno Thread

    Comment

      #3
      That's what I'm thinking. With the harness plugged into the DME I'm back probing the pins for the CPS and the ohms double when power hits the it from the main relay, 1020 ohms. Is that supposed to happen?

      When I switch the DMM to DC it jumps around like the CPS is generating a square wave, same on AC. I'm just wondering if the doubled ohms at power on is preventing the DME from fueling, sparking, and grounding relays.

      Can somebody back probe their harness and tell me if this is what's supposed to happen with a good CPS?

      Comment

        #4
        I'll take "Why is the CPS seeing voltage from the main relay in the first place? For $200, Alex."

        Looks like i have some wire chasing to do. FML. Tomorrow I will gut all unnecessary wires from the harness, move the Diag connector to it's original E30 home, and sort out this fiasco... New CPS in hand, but won't go in until I'm sure it's ready & needed.

        I forgot to mention. The first cranking attempt was without attaching that main ground to the strut tower. And i originally had the IAC connector plugged into the CPS. But from what I can see, none of the wires are burned from trying to find a ground, but maybe that's what happened to the CPS...

        This is my typical style, "Fuck it up the first time so you can learn what not to do the hard way."

        I'm always open to advice/words of experience. Feel free to chime in any time guys.

        Comment

          #5
          Ground to pin 66 and it fired right up. FML. I knew that CPS was fine.
          • Likes 1

          Comment

            #6
            I just spend like 2 days doing diagnosis and your pin 66 to ground worked thank you so much!

            Comment

            Previous template Next
            Working...
            X