Injector Flow Test 2015 GM Truck 5.3 L83 Glitch?

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  • phill57
    Senior Member
    • Oct 2007
    • 474

    Injector Flow Test 2015 GM Truck 5.3 L83 Glitch?

    Hello

    I was working on a 2015 GMC Sierra 5.3 L83 engine a couple weeks ago and was chasing a P219B code for fuel imbalance. I ran an Injector Flow test using my Verus Edge which at that time was running 20.4 software. The test results (see below) suggested all injectors on the right bank were flowing greater volumes than the left side. (greater pressure drop). After replacing all 8 injectors and carbon blasting the intake valves I got basically the same test results. I have since updated to 21.2 software and the test results are the same. I have tried running the same test on a 2016 and a 2017 which have no issues that I am aware of and got the same results. Bank 2 injectors consistently drop about 10psi greater than bank 1?

    On another note since updating to 21.2 the test only shows cylinders 1 through 6 as the test is being run but actually appears to test all 8 cylinders.

    The 1525 file is before replacement and the 1554 is after replacement and shows the missing cylinders 7 and 8 in the top left corner.

    I have trouble believing the test results and was wondering if anyone has done the test using GDS2.
    VIN on this 2015 was:3GTU2TEC0FG217472

    Here is a video where the test starts at 19.54 min in:
    Attached Files
  • Steve6911
    Moderator
    • Feb 2007
    • 2168

    #2
    Thank You Phil, I will forward your report

    Comment

    • JBakke
      Senior Member
      • Jul 2012
      • 6662

      #3
      Your submission has been added to our tracking system #168429

      Comment

      • dbarnes5654
        Senior Member
        • Apr 2007
        • 123

        #4
        Glitch

        I haven't run a fuel injection test in a long time but if I remember correctly, it is ran koeo .
        I noticed you have a rpm pid in the tests you posted. Try the test with koeo and see if the results are different.

        Comment

        • phill57
          Senior Member
          • Oct 2007
          • 474

          #5
          Injector flow test

          As far as I know the injector flow test on the GDI systems is done while running. Not like the older port injection systems.

          Comment

          • Glide
            Senior Member
            • Jan 2015
            • 303

            #6
            Yes it is done with vehicle running.Just my two cents,I wouldn't condemn a injector just based on this test.The AFIT is the accepted tool .
            Also before ordering injectors for 14 and up TSB# 20-NA-098 should be read.

            Comment

            • JBakke
              Senior Member
              • Jul 2012
              • 6662

              #7
              Our development team has reviewed your submission and has the following findings:

              Only the the pressure drop values the controller returned are displayed. All cylinders are using the same conversion equation.


              The current implementation is as designed and no changes have been made. Please let us know if there are any additional questions regarding this issue.

              Comment

              • zjeep
                Junior Member
                • Jun 2008
                • 25

                #8
                Every truck I have run this test gives same result. Different pressure from B1 and B2 , B1 is always lower pressure Even with NEW injectors. So how is this test useful ?

                Comment

                • zjeep
                  Junior Member
                  • Jun 2008
                  • 25

                  #9
                  Also get same result with GDS2.

                  Comment

                  • Glide
                    Senior Member
                    • Jan 2015
                    • 303

                    #10
                    Despite this test being labelled as "injector flow test",it is just a injector balance test.The most usefull PID is RPM (drop).

                    Comment

                    • zjeep
                      Junior Member
                      • Jun 2008
                      • 25

                      #11
                      Then what's the purpose of the power balance test. Not trying to be smart axe just trying to learn something.

                      Comment

                      • Glide
                        Senior Member
                        • Jan 2015
                        • 303

                        #12
                        Originally posted by zjeep
                        Then what's the purpose of the power balance test. Not trying to be smart axe just trying to learn something.
                        If the rpm drop when the injector is disabled is less than the other cylinders,that would indicate that that injector is passing less fuel.This only works if the cylinder isn't dead for another reason (incorrect voltage or ground to injector,spark,compression).At least it sends you to the affected cylinder(s).
                        '14 and up GM gas vehicles can have up to three different flow numbered injectors,see the TSB that I referenced in a previous post.GM has a 'Active Fuel Injector Tester" to test individual injectors.
                        No scan tool is a magic wand.

                        Comment

                        • zjeep
                          Junior Member
                          • Jun 2008
                          • 25

                          #13
                          Glide, thank you for your replies. I am aware of everything you said, I guess I was trying to use the test not the way it was designed to be used. I assumed it was like the older injector balance test that was done KOEO. I know you have to run GDI KOER.

                          Comment

                          • Glide
                            Senior Member
                            • Jan 2015
                            • 303

                            #14
                            Yes,the injector balance test was better for watching pressure drop for sure.

                            Comment

                            • phill57
                              Senior Member
                              • Oct 2007
                              • 474

                              #15
                              glitch

                              Originally posted by JBakke
                              Our development team has reviewed your submission and has the following findings:

                              Only the the pressure drop values the controller returned are displayed. All cylinders are using the same conversion equation.


                              The current implementation is as designed and no changes have been made. Please let us know if there are any additional questions regarding this issue.
                              I don't understand what that means. with the older software it would show 8 cylinders while it was testing them then with the current software it only shows six cylinders even though it appears to test all 8. Please look at the two images I posted.

                              The test is a waste of time in my opinion anyways. I have tested several trucks that don't have any know problems and the all test lower on bank 1. This even comes up using GM GDS so it's not the scan tool at fault. I wonder if it has something to do with the location of the fuel rail pressure sensor as it is on the rail on bank 1.

                              Comment

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