GM Injector Balance test

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • Witsend
    Banned
    • Nov 2012
    • 2942

    GM Injector Balance test

    I don't know if I would have bothered to do fuel injector cleaning of a vortec spider injector assembly and doing a injector balance test on a Blazer with out first verifiing compression test , and test cylinder leakage, on the two cylinders with high misfire counts while the 2 plugs were out Next, check stuck open EGR valve , or defective aftermarket distributor cap.
    What caught my attention in video is the cool Injector Balance test capability of the scantool,( performed after 15minutes into the video) I haven't tried it on mine yet. I didn't notice injector balance test for other makes and models.

  • maven
    Senior Member
    • Mar 2014
    • 269

    #2
    That test has been in GM tools for probably two decades now. Thats why its in the aftermaret tools, the vehicle ECM allows it. Its not a "custom" test that a tool maker came up with. Thats also why you wont find it on all the other makes in the same scan tool.

    Comment

    • Witsend
      Banned
      • Nov 2012
      • 2942

      #3
      The GM injector balance test appears to more manually involved and not automated start to end like Ford's relative fuel injector flow test because the GM injectors are individually selected manually and ignition key cycled to off then on to prime the fuel rail back up after manually writing down the pressure drop before selecting the next one, one at a time. The benefit of GM injector balance test might be is that you may just want to compare one suspect cylinder's (with a lot of misfires) fuel rail pressure drop to one known good cylinder injector, and not have to test and compare pressure drops on the rest .
      I guess if the manufacturer doesn't offer the scan tool option, some tool makers do offer a custom kit to do test manually if you can access the injectors or a connector where the wires lead to the injectors .

      The automotive injector pulser tool also called, the Wow Injector Pulser Tool is a high accuracy fuel injector testing pulser tool used for injector flow tests.

      Comment

      • Witsend
        Banned
        • Nov 2012
        • 2942

        #4
        I think I need to look into getting one of these fuel injector testing tool, like Scanner D. uses in this Vid. Love his Vids BTW

        Comment

        • Modis500
          Senior Member
          • Sep 2012
          • 358

          #5
          Crusty turned me onto the MT290 over a year ago and it has helped me quite a lot with driveability concerns. Best $75 I spent and has paid me back already.
          "If you aim for nothing, you'll hit it every time!"
          Zig Ziglar

          Comment

          • Crusty
            Senior Member
            • Dec 2007
            • 2450

            #6
            Originally posted by Modis500
            Crusty turned me onto the MT290 over a year ago and it has helped me quite a lot with driveability concerns. Best $75 I spent and has paid me back already.
            It's a dandy little tool-!! You need to make up some pin size jumpers for the newer vehicles and that can be a bit of a challenge but most recycle yards can help out thete.

            When I picked that handy little tool up a couple of DECADES ago, it set me back over $300 shekels in Beaver Bucks.

            Glad you found one that was inexpensive.

            Maven is right. The GM's have had the capabilty to do the same injector turn on command for quite a while now. Still need an ACCURATE pressure gauge but it does tell you how much fuel is flowing through.

            None of these tests will tell you if the fuel is ATOMIZING properly or how good the spray pattern is but it's a pretty good start.

            CURRENT RAMPING the injectors while you use the injector tester and a guage usually identifies faulty injectors most of the time.

            Comment

            • hhong12dlm
              Junior Member
              • Mar 2013
              • 22

              #7
              None of these tests will tell you if the fuel is ATOMIZING properly or how good the spray pattern is but it's a pretty good start.

              CURRENT RAMPING the injectors while you use the injector tester and a guage usually identifies faulty injectors most of the time.
              good idea, I never thought of doing it that way

              Comment

              • maven
                Senior Member
                • Mar 2014
                • 269

                #8
                And that little matco tool looks line a decontented version of the GM special tool thats been around since the 90's. It allows you to measure injector coil resistance as well.

                Theres also the newest "ACtive Fuel Injector Tester" (AFIT)that GM currently uses (its made by Waekon/Hickock) which uses an electronic fuel module as well and it measures pressure drop, fuel system pressure bleed down, injector resistance all through one set of tests. Its pretty comprehensive little tool, even works on direct injectors, but is STUPID expensive with the adapaters for DI, and isnt cheap even without them. It does come with semi generic harnesses for older or nonGM vehicles as well even if you buy the GM branded one.
                Attached Files

                Comment

                • Witsend
                  Banned
                  • Nov 2012
                  • 2942

                  #9
                  Maven I think I see something that's probably a Predecessor being sold used on e-bay.It's still not cheap



                  I"m wondering as far as cleaning if it would be more effectively cleaned to pull a restricted injector that tests good on an amp ramp and somehow seal and pressurize the exit nozzle side of the injector with hi pressure cleaner and activate the injector to get any hard particulates flushed out of the screen on the entry side? I'm sure it would only dribble but might be enough to clear the tiny screen without disassembly or having to get a rebuilt one.Most reman injectors are cheap enough to not waste any more time triing to clean one or two off the vehicle.
                  Last edited by Witsend; 03-09-2015, 05:47 PM.

                  Comment

                  • Crusty
                    Senior Member
                    • Dec 2007
                    • 2450

                    #10
                    That's what GM calls the AFIT tester.

                    A tool like the Snap-On MT290 (or using the GM injector test in the scan tool) plus a guage, along with a current probe and a decent multimeter will do the same things.

                    It's all about knowing what to look for and knowing what your existing tools will do.

                    An injector is an electrical coil that creates a magnetic field to pull a piece of metal to a different position.
                    Basically it's just like a relay that when opened allows fuel to spray. You can see a lot of the activity with a low current probe and a Vantage-PRO and a guage once the injector is activated.

                    The only thing we CAN`T see is the QUALITY of the atomization (but some people with a LOT of practice have become good at recognizing a good injector vs a bad one just from the current ramping) (I still need to learn that but necessity hasn't forced me to yet)

                    GM has several TSB`s on the both the AFIT tester and cleaning injectors but I don`t think the AFIT tester is really necessary.

                    Comment

                    Working...