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    Head swap no start problems

    I acquired a "rebuilt" 2.7 with 885 head. After install (using a standard I wiring harness) it turns over but won't start. I'm getting fuel and stark but all I'm getting is an occasional loud pop from the exhaust. It seems similar to the pop you get when trying to start a car thats timing is off. Any ideas about why could be causing this?
    The only other odd symtom is the fuel pump running about 5 seconds after I shut the key off.

    #2
    Im not a professional and I have only been dabbling with these things off and on but, sounds like maybe your using an incorrect Dme and/or your engine is seriously out of time. Unless you know what your doing and what you got swapping head parts harnesses and chips just plugging, playing, and praying.......it can turn out pretty bad. Id make sure the ecm is compatible with the harness i dont mess with really swapping engines and engine management systems but id start there make sure thats kosher if it is id remove the head set it TDC, set the bottom end TDC MAKE SHO FO SHO!! Your top dead center then go from there. Hopefully this helps

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      #3
      Your guess at timing seems to be the most likely. How did you check cam timing when reassembling the engine?

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        #4
        Whenever buying a project of someone else's you should check over their work. Make sure timing marks are correct for timing belt. That you have correct DME correct CPS, injectors, fpr, ignition wires and other stuff for 885 head swap.
        But first...
        Is the build motronic 1.3? If so... Do you have a 173 or 525 ecu? Front mount CPS and harmonic balancer (toothed wheel)and 325i ignition wires (will have a reference sensor on the 6th plug, also make sure these wires are in correct order. These could possibly be your issue. But we need more info

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          #5
          Also if its 1.3 check your ecu is 173 or 525 and open it to make sure you have a chip (stock or not)

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            #6
            Most likely cam timing. It's a common mistake to set it 180 degrees off because the crank marks will still line up. Also once you set the timing belt properly, rotate the engine at least two full turns to make sure the marks still line up. Belt slack can hide and put you a few teeth off.
            1989 325i Lachssilber Sedan
            5-Speed Swapped
            M30B35 Swapped
            MegaSquirt MS3X

            1987 325i Lachssilber Sedan
            260k OEM Automatic Daily Baby

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