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homo m20 spark/electronic gremlin bs

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    homo m20 spark/electronic gremlin bs

    its an seta based 2.7i with 173 dme.

    for about a week now, my car had been driving nice and strong, until it hit about 4500-5000 rpm, where it feels like it would hit a rev limiter. this would only happen under load, and in neutral it would rev to 7k.

    two days ago i had left home for some errands. the car ran just fine, still strong BUT still had that problem under load.

    on my way home, i had noticed that the car would run poorly and erradically through any rpm range. it wouldnt rev without misfiring if it revved at all. i made it to the end of my 8th mile long driveway, where the car finally called it quits.

    it will start, try to idle but missfire and sound like shit, then die. even if i keep my foot on the gas, it does me no good. it just misfires worse and barely stays alive.


    things ive done:
    replaced fuel pump relay
    replaced fpr
    replaced tps
    tried another afm
    checked for vac leaks
    checked ign wires and plugs, both are just fine.

    fuel pump is maybe a year or so old, i replaced with a new unit from bmw.



    things i want to try
    new cap and rotor and ign coilpack
    different dme


    NOTE:
    i have had the battery disconnected as i was working with the fuel, but i went to reconnect it and start it, but the car didnt have anough juice to do anything but keep the lights on. and in the past couple of days, whenever i hit a tiny bump or drove over a rough road, the stereo would skip bad.

    this is making me think that there is a loose ground somewhere, and its causing all of my problems.
    My feedback:
    http://www.r3vlimited.com/board/showthread.php?t=186328

    http://e30tech.com/forum/showthread.php?t=74911

    Instagram:
    @gears_n_glory

    @functionmotorsports

    #2
    Given those symptoms the first things I suspect would be:

    Low battery and a weak alternator
    Bad ignition wires/rotor, distributor cap
    Bad CPS
    Bad harmonic balancer
    Bad fusible link
    Bad DME

    Start at the top and work your way down
    The car makes it possible, but the driver makes it happen.
    Jim Levie, Huntsville, AL

    Comment


      #3
      Originally posted by jlevie View Post
      Low battery and a weak alternator
      Bad ignition wires/rotor, distributor cap
      Bad CPS
      Bad harmonic balancer
      Bad fusible link
      Bad DME

      did the cps, going to do the rotor/cap and dme tomorrow.

      i have no idea what the harmonic balancer is.

      i was thinking a bad alternator is my culprit at first... but for the car to missfire because of it? i think its unlikely.

      fusible link. you mean an inline fuse? i know e30 use them but i dont know where theyre hiding.
      My feedback:
      http://www.r3vlimited.com/board/showthread.php?t=186328

      http://e30tech.com/forum/showthread.php?t=74911

      Instagram:
      @gears_n_glory

      @functionmotorsports

      Comment


        #4
        The harmonic balancer is the wheel on the front of the engine that has the teeth read by the CPS. It is a two part assembly bonded together with rubber. If the bond fails or the balancer gets bent the DME can loose timing data at high rpm.

        A weak alternator that is allowing the battery to run down may result in insufficient system voltage at high rpm when the load on the DME is the greatest. More or less browning out the DME. The fusible link is in the smaller of the two wires that run from the positive battery terminal. It is covered in shrink wrap and is close to the battery.
        The car makes it possible, but the driver makes it happen.
        Jim Levie, Huntsville, AL

        Comment


          #5
          its starting to sound like the alternator now.

          the motor used to cut out at high rpm and come back on.

          im going to try different ign coils and wires and a cap and rotor to eliminate them as a cause.


          but the balancer could be what's causing the other problems.

          ugh.
          My feedback:
          http://www.r3vlimited.com/board/showthread.php?t=186328

          http://e30tech.com/forum/showthread.php?t=74911

          Instagram:
          @gears_n_glory

          @functionmotorsports

          Comment


            #6
            i tried an ign coil, dme and wires. no difference, actually it made it not even run after it would crank over.... im out of ideas.
            My feedback:
            http://www.r3vlimited.com/board/showthread.php?t=186328

            http://e30tech.com/forum/showthread.php?t=74911

            Instagram:
            @gears_n_glory

            @functionmotorsports

            Comment


              #7
              got it to finally idle, but i think im not getting fuel to a cylinder. it idles level, and revs but its not smooth: it feels rough. im going to pull the VC just to make sure its not a rocker. it does not missfire any longer, but it does not sound the way it used to.
              __________________
              Last edited by bataangpinoy; 06-13-2010, 06:24 PM.
              My feedback:
              http://www.r3vlimited.com/board/showthread.php?t=186328

              http://e30tech.com/forum/showthread.php?t=74911

              Instagram:
              @gears_n_glory

              @functionmotorsports

              Comment


                #8
                im having similar sypmtoms except my car still runs. Yesterday I drove my car without an oil cap on for 120 miles down the highway. If you figure this out let me know!

                Comment

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