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    Rebuilt Injectors Won't Fire

    About two years ago, I had a set of M20 injectors sent out to be cleaned/rebuilt/tested. Long story short, I was in a hurry to finish a car I was building for a customer and the injectors didn't fire when I installed them in the car. I had another set on hand, swapped them in, they worked fine, and I set the rebuilt ones aside.

    Fast forward to now and I'm rebuilding another M20 and dug out the rebuilt injectors again and tested them alongside the 200k mile units from this M20. Testing them on the bench with a 12v source, the rebuilt units DO NOT click when I apply power. The 200k mile units click strongly, so I know what they're supposed to feel and sound like. The rebuilt units test out correctly at about 16 ohms.

    Are these injectors just stuck? Any thoughts to getting them going again?

    Thanks.
    '89 BMW 325is Zinnoberrot / '88 VW Jetta GLI 16v Tornado Red / '89 VW Jetta GLI 16v Tornado Red / '89 VW GTI 16v Bright Blue Metallic / '91 BMW 325i Black / '91 BMW 325i Sport Black / '92 VW GTI 16v Black / '92 VW GTI 16v Montana Green / '01 Audi A4 Avant TQM Silver Metallic / '01 VW Jetta GLX VR6 Black

    #2
    Are all the injectors not clicking? It's hard for me to believe that they all stuck. It sounds like the rebuild did not go right. Try to disassemble one of them and do the rebuild yourself.

    Comment


      #3
      Correct, none of them click. What's odd is that my understanding of an injector rebuild comprises a new spacer, pintle cap, seals, and filter. Along with an ultrasonic cleaning. None of the new parts deal with the heart of the injector which is the coil and that is the part that isn't working. I'm not sure how a rebuild could have caused what I'm seeing, even if it didn't go right...
      '89 BMW 325is Zinnoberrot / '88 VW Jetta GLI 16v Tornado Red / '89 VW Jetta GLI 16v Tornado Red / '89 VW GTI 16v Bright Blue Metallic / '91 BMW 325i Black / '91 BMW 325i Sport Black / '92 VW GTI 16v Black / '92 VW GTI 16v Montana Green / '01 Audi A4 Avant TQM Silver Metallic / '01 VW Jetta GLX VR6 Black

      Comment


        #4
        If by chance during the rebuild, the injectors were not primed with a lubricant, they can certainly stick (specially if the ultrasonic was done with straight water, or diluted soap).

        BTDT!
        john@m20guru.com
        Links:
        Transaction feedback: Here, here and here. Thanks :D

        Comment


          #5
          Originally posted by ForcedFirebird View Post
          If by chance during the rebuild, the injectors were not primed with a lubricant, they can certainly stick (specially if the ultrasonic was done with straight water, or diluted soap).

          BTDT!
          Makes sense to me. Any good ways to unstick them?
          '89 BMW 325is Zinnoberrot / '88 VW Jetta GLI 16v Tornado Red / '89 VW Jetta GLI 16v Tornado Red / '89 VW GTI 16v Bright Blue Metallic / '91 BMW 325i Black / '91 BMW 325i Sport Black / '92 VW GTI 16v Black / '92 VW GTI 16v Montana Green / '01 Audi A4 Avant TQM Silver Metallic / '01 VW Jetta GLX VR6 Black

          Comment


            #6
            Never found a way to reliably to free them. :(
            john@m20guru.com
            Links:
            Transaction feedback: Here, here and here. Thanks :D

            Comment


              #7
              Yeah, I've always gone under the impression, don't get your injectors rebuilt until you are ready (or nearly ready) to install. They will go bad - quickly. Without sending them back out again, you'd be taking risk trying to free them up yourself.
              1991 325i MT2 Touring (JDM bro)
              2016 Ford Flex
              2011 Audi A3 - wife's other German car

              Comment


                #8
                They can be stored after cleaning, they just have to be primed with a lubricant. Even used injectors that sit for a lengthy amount of time will stick once the fuel varnishes. Electronic parts lube (contact cleaner/lube) works great for storage.
                john@m20guru.com
                Links:
                Transaction feedback: Here, here and here. Thanks :D

                Comment


                  #9
                  ^^^ Agree

                  Originally posted by Cinnabar325is View Post
                  Makes sense to me. Any good ways to unstick them?
                  I took mine to Dr. Injector. The owner said that if I wasn't going to install them within a week or so that I should bring them back to wake them up. Little I knew that my rebuild was going to take a year. A few weeks ago I took them back and they were stuck. They guy pretty much slammed each one against the bench and then tested each one to make sure they clicked. He said that the cleaning solution dries out and the inside components get stuck. He assured me that they are now free and it wouldn't matter if I don't get them started soon.

                  Comment


                    #10
                    shit, now I am worried about my injectors I had rebuilt (by BMWStone) that have been sitting for maybe 3 months. Should I be worried about starting up the car??

                    They guy pretty much slammed each one against the bench and then tested each one to make sure they clicked. He said that the cleaning solution dries out and the inside components get stuck. He assured me that they are now free and it wouldn't matter if I don't get them started soon.
                    is that recommended? To just beat them on a table?? Any reliable ways to free them up without another rebuild? they are already mounted to my fuel rail and intake and installed, should I honestly take them out now to rehab them? I took them out of the clean plastic baggies they came in and then directly put them into the rail/intake, but again, after 3 months.

                    They can be stored after cleaning, they just have to be primed with a lubricant.
                    how and where would you apply this lubricant? I will be needing to do this soon...
                    Last edited by BaltimoreBimmer; 05-31-2017, 06:38 AM.

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