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M20B23 Identity Crisis

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    M20B23 Identity Crisis

    First post! Hit a wall with this and finally had to quit lurking and register..

    Anyhoo, I've got an '85 euro E30 with some fueling issues that have so far eluded me. I originally purchased this with the intention of making it my daily driver but haven't had a helluva lot of time to sort it out to the point where I feel comfortable parting ways with my current (Japanese.. I know) car. So it's sortof become an every-other-daily driver during the weeks when it isn't in the garage with some of its guts laid out on the work bench.

    I won't go into the details of my EFI woes in this thread - that's a long story for another time. My immediate problem is that of my Cold Start Valve (aka Cold Start Injector or Starter Valve) or puzzling lack thereof.

    See, I'm fairly certain this car is supposed to be equipped with one - the '85 323i should have an M20B23 with L-Jetronic fuel injection. L-Jetronic systems use a Cold Start Valve to enrich the mixture upon a cold start. My Bosch fuel injection book says so and so does the UK Haynes manual I found, the latter even has a procedure section about removing it but the b & w photo is too zoomed in to give any context for where the thing is supposed to live or what it really looks like. That Haynes book is a shit manual compared to the Bentley but I can only use the Bentley for things common to US models and the EFI on an M20B23 isn't one of them. The Bosch book is quite detailed but it talks about L-Jetronic in a generic, multi-application sense that's not specific to a certain car. Regardless, both books have similar diagrams that each indicate a Cold Start Injector should be kicking about somewhere.

    When you enter in the last 7 digits of my VIN (9604914) to RealOEM, it tends to agree and lists a "Starter Valve" on both the Intake Manifold and the Fuel Injection System schematics as item #7 on the former and #9 on the latter:


    Great, right? So, while doing some L-Jetronic research/diagnosis on my lunch break at work I go ahead and order one (P/N 13641285087 from RealOEM, 0280170043 equivalent on AutoHausAZ) without waiting to get home and actually look at my old one. Whoops.

    Imagine my surprise when, once the new one had arrived, I couldn't seem to find and old one to replace with it! Not only that, but I can't even find where this thing is supposed to mount. The first diagram above seems to imply that it would bolt up to the "Connection Flange" listed as item #5 in the Intake Manifold diagram from RealOEM. Am I wrong?

    Well, as it turns out, that face on the Connection Flange is blanked out on my manifold. I can see some features in the casting that would allow for the mounting holes to be reamed out and tapped but there's no hole for the nozzle/barrel of the Cold Start Valve to plunge into or the o-ring to seat in, just a flat circle about the size of a quarter.

    Sooo, I'm perplexed. Does anyone know what this might mean? Is this blanked out Connection Flange typical of any other M20 variation? Is there a way to tell at a glance if this is in fact the 2.3 euro engine? Perhaps I'm misunderstanding the diagram and the Cold Start Valve is buried elsewhere? Any tips on pursuing this further?
    '75 Honda CB400f
    '85 BMW 323i Euro
    '04 Acura TSX A-Spec

    #2
    Ever heard the phrase "a picture is worth a thousand words?"
    "I'd probably take the E30 M3 in this case just because I love that little car, and how tanky that inline 6 is." - thecj

    85 323i M TECH 1 S52 - ALPINEWEISS/SCHWARZE
    88 M3 - LACHSSILBER/SCHWARZE
    89 M3 - ALPINEWEISS II/M TECH CLOTH-ALCANTARA
    91 M TECHNIC CABRIO TURBO - MACAOBLAU/M TECH CLOTH-LEATHER

    Comment


      #3
      I have, or should I say had an '85 323i. I have ditched the motor in favour of a B25. I can't advise you what is what, however whilst trawling around on RealOEM I found this.
      Click image for larger version

Name:	323i throttle Dia.png
Views:	1
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ID:	7151365
      P/N 30 CONTROL BOX 1 13541289039 $231.96
      I think is the part your chasing. I could well be wrong and as I said I don't have the engine anymore for reference. It uses vacuum to control the throttle springs/butterfly valve.

      Hope this helps

      Comment


        #4
        Im guessing you dont have a 323 engine and someone swapped in a different one, take a pic of the engine for us. if your saying your car doesn't have the nipple on #5 on the top diagram (the plate for vacuum lines on the passenger side of the intake manifold) that points to the rear of the car and goes to the cold start valve..

        here is a pic of a 325I engine


        325E engine


        and a 323 euro engine
        sigpic

        Comment


          #5
          Originally posted by reelizmpro View Post
          Ever heard the phrase "a picture is worth a thousand words?"
          Here are two photos:



          (They're large so I didn't want to embed them)

          Originally posted by Saascat1 View Post
          I have, or should I say had an '85 323i. I have ditched the motor in favour of a B25. I can't advise you what is what, however whilst trawling around on RealOEM I found this.
          [ATTACH]65488[/ATTACH]
          P/N 30 CONTROL BOX 1 13541289039 $231.96
          I think is the part your chasing. I could well be wrong and as I said I don't have the engine anymore for reference. It uses vacuum to control the throttle springs/butterfly valve.

          Hope this helps
          Thanks very much mate but I know the name of what I'm after and where to find it on RealOEM, just can't find it out in my garage! Thanks for the input though.
          '75 Honda CB400f
          '85 BMW 323i Euro
          '04 Acura TSX A-Spec

          Comment


            #6
            Originally posted by e30Rooster View Post
            Im guessing you dont have a 323 engine and someone swapped in a different one, take a pic of the engine for us. if your saying your car doesn't have the nipple on #5 on the top diagram (the plate for vacuum lines on the passenger side of the intake manifold) that points to the rear of the car and goes to the cold start valve..
            I think it has the nipple pointing toward the rear of the car, it's just that the port facing the passenger side (that the Cold Start Valve would plug into) isn't there! See my two pics linked above for this blank face that still seems to have the mounting holes for the CSV..

            Thanks for the pics! I can say from memory that the 325i engine is drastically different from mine and I can see the Cold Start Valves on both of the other ones (in the 323 euro pic it doesn't seem to be connected to the fuel line or control wire but it's mounted). I will be able to post better pics of my whole engine bay tomorrow..
            '75 Honda CB400f
            '85 BMW 323i Euro
            '04 Acura TSX A-Spec

            Comment


              #7
              I see some with and some without. Now to figure out why. What year is your car? RealOEM shows models up to 9/84 used cold start valves (starter valve). Those produced after did not. Just because it's in the diagram doesn't necessarily mean it's applicable to your car. You have to pay attention to the dates the parts were used.

              Early 323


              Later 323
              Last edited by reelizmpro; 01-29-2013, 05:07 AM.
              "I'd probably take the E30 M3 in this case just because I love that little car, and how tanky that inline 6 is." - thecj

              85 323i M TECH 1 S52 - ALPINEWEISS/SCHWARZE
              88 M3 - LACHSSILBER/SCHWARZE
              89 M3 - ALPINEWEISS II/M TECH CLOTH-ALCANTARA
              91 M TECHNIC CABRIO TURBO - MACAOBLAU/M TECH CLOTH-LEATHER

              Comment


                #8
                Originally posted by reelizmpro View Post
                I see some with and some without. Now to figure out why. What year is your car? RealOEM shows models up to 9/84 used cold start valves (starter valve). Those produced after did not.
                /facepalm

                Welp you appear to have solved the mystery: mine's a July '85 car. Thanks very much.

                Back to the drawing board..
                Last edited by bloodsnot; 01-29-2013, 05:24 AM.
                '75 Honda CB400f
                '85 BMW 323i Euro
                '04 Acura TSX A-Spec

                Comment

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