Nistune Forums

can;t tell if this is a tuning or mechanical issue but im going nuts trying to figure it out. it just started happening recently so heres a run down of my set up and whats going on.

RB25det s2
gt3582r
detschworks 740cc injectors
tomei type s FPR set to stock fuel pressure 43.5 psi
nistune in z32 ecu
walboro 255plh pump hardwired to battery and relay
z32 fuel filter

i think thats all you really need to know anyway my car randomlyy starteds acting up on the dyno, i did 385whp 340/lb tq on 15 psi but i was leaning out up top, well now when i go out and rip on it it gets dangerously lean like 13.5 afrs+ after 5500 rpm. i can change my maps and as you can see in the screen shot i tried to richen it up up top and higher load and it does nothing, leads me to belive its a mechaincal issue but idk. i never changed anythign in my tune and this started happening. i did try two different fuel pumps with no problem but now im just completely stumped, i can;t see my fuel pressure while in car so i want to get a way to get my gauge inside the car to watch it while doing a pull. if anyone has any ideas though i would greatly appreciate it because im out of ideas. heres a scren shot of a log i did and when i let off you can tell by the TPS is when it leans out to a dangerous level. also i see injection time but i have no idea how the hell do i figure out injector duty cycle????

https://picasaweb.google.com/1016243590 ... 4938296946

Log file with injection time, TP, RPM, AFM voltage and AFRs will help us look into it

how do i find injector duty cycle? i cannot find it anywhere in the nistune software

It shows up on the gauges when you enable 'injector time' which is required to display it

i have injector time RHS but i do not see duty cycle anywhere! i even went into operations>select display gauges and theres no option for it!

Duty cycle is based from Injector time LHS

ok great got it thanks matt!. injectors are showing a 45% duty cycle right now which seems normal for 740ccs making about 380whp right now. still unsure about why this car is leaning out. i will upload a bin and log file for you to look at. i don;t have a way of logging afrs quite yet though so i want to try to get that set up. its going to make things a lot easier im sure. i did eliminate any mechanical issues though. i swapped out like every part of my fuel system besides injectors and it didn;t change anything.

You have to multiply injector duty by 2 to get the correct value, as it is the opening time and injectors opens twice .

Check you fuel filter / fuel pump sock.