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Installed new engine - won't start

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    #1

    Installed new engine - won't start

    I just installed a new (used] M20B25 engine in my 1990 325i since I blew a rod through the block during a Spec E30 race at Mid-Ohio.

    Anyway ... It won't start. Starter turns great but no fuel. Voltage is getting to the junction box, but no voltage checks out at the main relay or the fuel pump relay. The fuel pump does work when a power source is directly fed to it. All connectors double checked.

    I know this sounds somewhat like what happens when the battery gets disconnected with the OBC anti-theft device, but if it is, I don't know how to fix it, and it's never happened b4 when battery re-connected. I only had the mini-obc with date/clock/temp instead of the whole elaborate OBC display but it got discarded when my dash came out when roll cage went in.
    Also, I'm not getting anything when I activate the fault code procedure - pressing pedal 5 times.
    Any help appreciated.

    See pics of the engines, including the damage, here -

    s184.photobucket.com/albums/x269/tomzzy/Spec%20E30%20engine%20change/

    -tom-
    Tags: None
    #2
    I would check the main fusable link

    Closing SOON!
    "LAST CHANCE FOR G.A.S." DEAL IS ON NOW

    Luke AT germanaudiospecialties DOT com or text 425-761-6450, or for quickest answers, call me at the shop 360-669-0398

    Thanks for 10 years of fun!

    Comment

      #3
      The first check is to see if the main relay closes and applies power to the DME. If not the relay could be bad or power isn't reaching the coil from the ignition switch.

      If you have power to the DME you need to check for the crank position sensor and its connection to the engine harness. It is easy to swap the cylinder ID and CPS plugs. With no timing reference signal the DME won't operate the fuel pump relay.
      The car makes it possible, but the driver makes it happen.
      Jim Levie, Huntsville, AL

      Comment

        #4
        Check for spark/fuel first thing. If you get neither, check CPS as mentioned above, and/or swap with a known good DME. Main relay could also keep power from getting to the DME like mentioned above.
        RIP e30 (brilliantrot '91 325i) 11/17/06 Byebye: 8/21/07
        Welcome e30 (brilliantrot '90 325is) 12/23/06
        DaveCN = Old Man
        My signature picture was taken by ME! Not by anyone else!



        Originally posted by george graves
        If people keep quoting me in their sig, I'm going to burn this motherfucker down.

        Comment

          #5
          check youve got the fuel lines going the right way and not reversed. been there, done that... twice


          Originally posted by vlad
          Do you know anybody else who built that many bad ass E30s?

          Comment

            #6
            Got it started! Wire off the harness was connected to the wrong place. Knew I was getting juice at the junction box, but none at the main relay. Found out which terminal in the ECU connecter was for the main relay and did continuity tests from there and the main relay to all wires, connectors coming out of the harness til I found it. Had one hooked to ground that should've been to the hot juice at the junction box. It's usually some dumb oversight like that. Thanks for all the suggestions. They got me thinking along the right track

            It's great to hear her purring again. It's been a real education for this first timer.

            tom

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