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iX Running Weird- Need Diagnosis Assistance

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    iX Running Weird- Need Diagnosis Assistance

    Hey fellers,

    I'm in need of R3V's assistance.

    Background:

    I recently put a new head (bimmmerheads, 280/274 regrind, hd rockers) on the ole '88 iX, along with a lightly ported intake manifold done by Curt Brown, and all new plugs, wires, cap, rotor, water pump, gates belt, gaskets, etc. The car has fresh M50 injectors and an SSSQuid chip for 93 octane, and a K&N drop in.

    The car ran well before I completed this work. The head was a hair noisey and the plugs/cap/rotor were long overdue, so I figured it was time to R3v this bish.

    Now:

    The car starts up, idles, and drives fine, however, it feels ridiculously low on power. You can notice in the way the car revs too, compared to my lil bros stock 250K M20. It feels like a dog. But it doesn't misfire. And there's no CEL. And it does everything fine. Just feels extremely slouchy. For example, it really hates revving if under 1K, and it revs very slow pretty much all around (which is the video I have attached below).

    I do E30 timing belts and maintenance at work all of the time, so I'm quite familiar with the platform. I triple checked the timing and it was dead on. No gasket leaks on the intake manifold, I cleaned the throttle body, etc. Can't find any vacuum leaks anywhere.

    Does anyone have any ideas on what could cause this? It doesn't really appear to 'pick up' on the top end either like it's just a cam that lost some low end. Just feels extremely lazy all around. The head was just 'cleaned up' by them, and had the ramps of the intake ports changed. I'm just wondering if the head and cam could make it lose all of it's grunt like that? I haven't readjusted the valves after driving it for a bit. Not sure if that could do it? I doubt it, though, as the old head the valves were lightyears out of spec and it ran fine.

    At first I just assumed it was normal, but something is definitely not right.


    In this idle video you can hear little 'pops' in the exhaust, specifically around 12sec. Kind of sounds exhaust valve related? I don't know. Also, you can hear the noisy valves that I guess need readjusting.




    In this video, pay attention to the throttle usage vs revs. Photobucket compressed it to death, so please excuse that.




    I don't know. Let me know what you think. Any help is very much appreciated.

    I'm off right now to do a wet and dry comp test and vacuum leak test.
    Last edited by AWDBOB; 01-24-2015, 12:22 PM.
    1989 Hooptie 325iS Build Thread
    1989 Zinnoberrot M3 Build Thread

    #2
    Update:

    Sprayed down all vacuum connections, no leaks found.

    Compression:

    Cyl 1: 151
    Cyl 2: 149
    Cyl 3: 147
    Cyl 4: 140
    Cyl 5: 135
    Cyl 6: 135

    Weird that they slowly increase back to front.
    1989 Hooptie 325iS Build Thread
    1989 Zinnoberrot M3 Build Thread

    Comment


      #3
      Do you have an a/f ratio gauge on it? Id find out what its running under wot.

      Comment


        #4
        Originally posted by TheTacoMan View Post
        Do you have an a/f ratio gauge on it? Id find out what its running under wot.
        No A/F gauge unfortunately. It revs slow all the way through the powerband, and stutters off idle, though, not just a power delivery issue at WOT, and there aren't any misfires except the stumble off idle.

        Here are brand new plugs after 15 miles. They all look similar.



        Checked AFM, removed air filter, didn't get any better. Sprayed around the IAC, the TB to IM, intake boot, all vacuum lines by the brake booster, injector orings, fuel pressure regulator, vacuum port on IM, breather hose on VC, etc while running, no fluctuation whatsoever.

        Wondering if the coil could be starting to go bad? That's pretty much the only thing that wasn't replaced when I was in there.
        1989 Hooptie 325iS Build Thread
        1989 Zinnoberrot M3 Build Thread

        Comment


          #5
          Have you checked ignition timing?
          E30 325ix M50 turbo 7 spd DCT 4wd 840awhp @ 31 psi.
          E30 M50 6 spd 764whp @ 24psi.
          E30 M20 6 spd 675whp.

          Comment


            #6
            Plug looks WAY rich. Light brown indicates a good mixture...

            Was the chip made for the correct injector sizes? Have you checked fuel pressure?

            My car had symptoms of horrible running when my return line to the tank go plugged, which drove fuel pressure through the roof and caused injectors not to open consistently (and run rich for spraying more fuel).

            Comment


              #7
              Originally posted by The Dark Side of Will View Post
              Plug looks WAY rich. Light brown indicates a good mixture...

              Was the chip made for the correct injector sizes? Have you checked fuel pressure?

              My car had symptoms of horrible running when my return line to the tank go plugged, which drove fuel pressure through the roof and caused injectors not to open consistently (and run rich for spraying more fuel).
              I thought the same about the plugs. That happened fairly quickly too. Chip is for the correct size injectors. I need to tee off my feed and get a gauge and see what's up with the richness, I've actually had a clogged return before too due to a new fuel pump assy not being drilled out correctly, but not on an e30. I'll check it.

              I did, however, seek to solve the off idle stutter and that 'pop' in the exhaust, and my theory on exhaust valves proved to be correct. I readjusted the valves on the new head and MAN were they tight. Like barely get a .004 in there tight. So I loosed everything up a bit, and wallah, revs fine off idle, and no more pop in the exhaust.

              I have to wait until the salty slush dries to feel the rest of it, but I still need to figure out the rich issue, and if the valves could've had that much to do with it to cause those plugs I'm not quite sure.
              1989 Hooptie 325iS Build Thread
              1989 Zinnoberrot M3 Build Thread

              Comment


                #8
                I ran a 284/272 on a bone stock M20, it ran really well. so I think something else is wrong.

                I would try stock injectors and a stock chip. it won't reach the full potential of your setup, but it should run just fine.

                also, over tightened vales will definitely muck things up. as the engine heats up, the gaps actually increase a little. So if they are too tight it will run like shit when it's cold.
                Build thread

                Bimmerlabs

                Comment


                  #9
                  Originally posted by nando View Post
                  I ran a 284/272 on a bone stock M20, it ran really well. so I think something else is wrong.

                  I would try stock injectors and a stock chip. it won't reach the full potential of your setup, but it should run just fine.

                  also, over tightened vales will definitely muck things up. as the engine heats up, the gaps actually increase a little. So if they are too tight it will run like shit when it's cold.
                  Well, I went for a spin today before the storm hit, and I must say, the valve adjustment made a WORLD of a difference. The car runs fantastic now. I'm going to get some fresh plugs and drive it again to see if it made a difference with the rich conditions too.
                  1989 Hooptie 325iS Build Thread
                  1989 Zinnoberrot M3 Build Thread

                  Comment


                    #10
                    Nice!
                    E30 325ix M50 turbo 7 spd DCT 4wd 840awhp @ 31 psi.
                    E30 M50 6 spd 764whp @ 24psi.
                    E30 M20 6 spd 675whp.

                    Comment


                      #11
                      Wow, how off was the spacing? Glad you got it figured out :up: (and it wasn't my fault :P)

                      Comment


                        #12
                        Originally posted by Nisse Järnet View Post
                        Nice!
                        Yeah!! She feels nice now, still needs a turbo though!

                        Originally posted by squidmaster View Post
                        Wow, how off was the spacing? Glad you got it figured out :up: (and it wasn't my fault :P)
                        It's all your fault!!!!!!!

                        The tightest of the bunch (lol) was about .002, supposed to be .012 warm. "They was tight."
                        1989 Hooptie 325iS Build Thread
                        1989 Zinnoberrot M3 Build Thread

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