Labscope Relative Compression Question

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  • #10969
    Woefman
    Participant

      I love your videos. My Favorite is your Geeky Relative Compression Video.

      I have all the tools you used.

      My question is on channel 2 how did you hook up the scope to the coil? The video is not clear to me on wheather a second amp clamp was used.

      Thanks So Much in Adavance.

      #11315
      Woefman
      Participant

        update …. The scope has ability to do amps (10 amps max) using the pos+ and neg- leads

        so i was wondering if you did ch2 that way or do you have 2 amp clamps

        maybe i should watch video again….ive watched it twice but on a stupid small screen(phone)

        Thanks

        #11722
        Woefman
        Participant

          Hello is this thing on????

          I find it funny, people post they need help with a car yet leave out important info i.e. Year Make Model and then some. And replies like crazy to those posts.

          I have legit question (video camera not pick up how connected ) and I get no response.

          #280199
          Aquaman53
          Participant

            Wolfman, he clipped the amp probe around the positive battery cable, at the battery. When placed around the battery cable, the clamp has to be completely closed. There should also be an arrow on the clamp indicating the direction of the flow of current from the battey.

            #280200
            Aquaman53
            Participant

              Woefman, he clipped the amp probe around the positive battery cable, at the battery. When placed around the battery cable, the clamp has to be completely closed. There should also be an arrow on the clamp indicating the direction of the flow of current from the battey.

              #281299
              dennis524
              Participant

                I think Woefman was asking about what he used to identify which plug was firing to identify the
                faulty cylinder using the firing order.
                I have the same question.

                #281831
                Apex
                Participant

                  You can use cylinder #1 COP or fuel injector on channel 2 as your identifier to determine which cylinder is your #1 cylinder, then count the compression events by firing order to determine the remaining cylinder numbers. There’s probably a lot more ways to do this.

                  I would probably simply use an inductive pickup over the COP (I believe this is how Matt did it), but if you have a DIS or distributor you could probably put a second clamp on the plug wire.

                  #282243
                  Arthurmax01
                  Participant

                    Good post….thanks for sharing.. very useful for me I will bookmark this for my future needs. Go check out my new blog: HP 49 Service Error

                    #282564
                    Georgesauto
                    Participant

                      You also can use the trigger signal sent to the coil on plug using another channel but note : if its a 2 wire COP then you need to have an attenuator in series with your scope channel to prevent damage to your scope . If the COP has more than 3 wires then you need to connect to the signal wire that has a square wave signal. Check wiring diagrams for the cop set up. The falling edge of the square wave is when the coil fires. I would avoid using a amp clamp as it can show multiple coil current draws at the same time for this particular test as it can mislead you regarding the firing order.

                      #282565
                      Georgesauto
                      Participant

                        You also can use the trigger signal sent to the coil on plug using another channel but note : if its a 2 wire COP then you need to have an attenuator in series with your scope channel to prevent damage to your scope . If the COP has more than 3 wires then you need to connect to the signal wire that has a square wave signal. Check wiring diagrams for the cop set up. The falling edge of the square wave is when the coil fires.you then need to verify the firing order of the vehicle using factory info.

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