Inj DC % not reading

very new to HP tuners just got it yesterday so im sorry if this question has been asked before but my injector duty cycle % is not reading ive watched multiple videos and still will not read any feedback would be great thank you

Duty cycle is not a channel you log, it's a math of the injector pulse width avg.

You need to be logging injector pulse width avg for both banks, then it will appear.

i have both injector pulse width bank 1 and 2 pins opened when i was log and still no reading

Post your data log here.

lol how do i do that?

Using the attachment feature is the advanced reply box.


I'll say this too. Whatever you wish to log must be present in the main channels list on the left in the VCM scanner. The channel has to be there for it to report in the graphs/charts/gauges.

like i said i just got it Saturday so im still trying to figure everything out

Add the channels to the channels list and it'll start working.

Looks to be running super rich too, fuel trims are way negative, maybe that's what you are working on already.

im also confused to as why most of the channels go away when you open a log is this normal?

i noticed that also but in all honesty i wouldn't even know where to being with changing them...i had the truck dyno tuned and he said my duty cycle was to high and that i need to get that fixed before he could continue

If a channel goes away when you start logging, it's likely not supported by that controller.



Now I don't know your whole story and all the mods you have done to the vehicle in question but if that was a legit response from someone that dyno tunes for a living, you need to run far far away.

Maybe he just doesn't understand that duty cycle is normally in direct relation to how the tune is setup, fueling wise or the engine makes too much power and the injectors aren't large enough.


If he says the duty cycle is too high, it's because it is either commanding way too much fuel or you are out of of injector headroom and pushing the injector beyond what is safe. Like anything over 90-100% duty cycle is too much at full throttle. This of course must be monitored with a wideband o2 sensor in the exhaust to see the real time air fuel ratio.

This guy should have told you if you needed larger injectors or if something else was wrong. And just going off the limited information at the moment I think something is fishy here because if the tune is that rich just at idle after a dyno session, I don't think he has a clue what's going on.

truck is a 2012 gmc sierra 1500 5.3 with a stage 2 turbo cam with a 75/96 turbo 88lb inj walbro 450 pump -8 feed and -6 return i did notice my fuel pressure is allover the place dont know if thats normal or not