GM 5.3 GDI Injector balance test results needed

Hi Tanner - so there really won’t be a “known good” for this. The results are an average of the specific vehicle you are testing and if you test 10 vehicles you can get 10 different results that are all good. Actually if you test the same vehicle 10 times you can still get 10 different results that are all good. If you are part of the CTI group take a look at the material for the GM class I…

I guess I should have specified what I am using it for. I’m building a case study from one that I diagnosed. I wanted data from one without the code so I could show that they will always be different and also show why the math equation gm gives doesn’t work that well.

"... but the bank with the pressure sensor will always be slightly skewed from the opposite bank - that is normal." Thanks for the confirmation, sir. I've always noticed the same thing, and put it down to system design and location of the rail pressure sensor. Does that sound right? Or is there a better explanation? My shop doesn't participate in Carquest training, unfortunately. What was…

I have some before and after from a '15 L83 with a persistent P050D and P0300. Lean miss on #3. Before: scanshare​.​io/share/KYPv4BsM… diag​.​net/file/f20hzbmts… After replacement of #1 and #3 injectors: scanshare​.​io/share/tAoZmGF… diag​.​net/file/f4xl5hqml… Next is from a '18 L83 that got a whole set of injectors for P0171/P0174 codes. Can't find the before, but here's the…

Tyler, I am a bit confused, it would appear #5 was worse than #1. What was the reasoning on choice of replacement.

Eric, I believe that's Tanner's point - it's actually a pretty useless test. ;) The reason for replacement of #1 and #3 was secondary ignition waveforms that indicated a lean miss, despite the balance test saying otherwise. Just for giggles, I ran the same balance test five times within three minutes on a '13 Equinox (LEA) with a P219A. The results didn't really help me...

I didn't glean from this that he had established lean misfire from secondary waveforms. That said, I won't put much if any weight on an injector balance test unless one is way out of the 'norm'. I also assume that replacement of all injectors would be the smart approach?

I just now saw this conversation, sorry for the delay. Eric, Tyler is correct on my reasoning. I fixed this vehicle by looking at the actual injector drop using the fuel pressure sensor and a pico. Mine had an analog sensor so that's why it was possible. Its also possible to look at the change in lambda during each injector turn off event and compare them to each other. The injector balance test…

Thanks, Tanner. I'd love to see that case study when its completed.

Tyler, in the 18 that got all new injectors the data appears maybe it is missing the decimal points in the numbers or maybe switched from psi to something else. Any idea?

Yeah, the Snap-On scanner and ShopStream drops decimal points occasionally. Another bug that's been around since forever.

Tanner, Have you gotten the information you need? I have a 2014 Silverado 1500 with the 5.3L GDI engine at the shop right now for A/C work. Could you detail what you would like me to do if you need more information? Regards, Timothy

Tanner, Have you gotten the information you need? I have a 2014 Silverado 1500 with the 5.3L GDI engine at the shop right now for A/C work. Could you detail what you would like me to do if you need more information? I'll be glad to give it a try. Regards, Timothy

I got the info I need, thank you!!

I don't have any from 5.3L engines but I have a couple from 2016 6.2L engines if you are interested. They look pretty much the same as the 5.3L.

Here the best I could on 2017 Tahoe this vehicle has 33,000 on it. Have another 2017 in my fleet and a 2020 which i can lie to on the 2020 Tahoe these all have 5.3L engine in them and get past the gate way module with the Zeus scan tool. Let me know if this Patten help. No code in the this vehicle as of the shot taken running like it suppose too.

Thank you!!!