Weirdest running rich problem above 3000rpm

[GT-R David]

Weirdest running rich problem above 3000rpm

Hi all.

Hope someone can help me with my problem.

I have an R32 GTR, freshly build RB28.

Mapped with Nistune. Car was running fine while we mapped it and also the day after that.

Next day it had the weirdest problem.

Car is running completly normal until exactly 3000rpm. Above 3000rpm the AFR drops to 10.5:1 instantly and stays there almost the entire rev range. Doesn't matter if I'm driving oder reving it in neutral.

It also doesn't matter what settings we make in Nistune. It's always the same above 3000rpm.

 

What we checked so far:

-both AFM have rising voltage with rev and load

-TPS has normal Voltage

-has 3000km old Splitfire coilpacks

-has 4000km old Mine's AFMs

-has 200km old Sard 850cc high impedance injectors and resistor delete

-tried a different CAS

-shows normal water temperatur

-shows normal IAT temperatur

-problem also happens with unpluged O2-Sensors.

 

Looks like some kind of limp mode to me, but can't figure it out.

I'm realy pissed with the car (again).

Hope someone can help me.

Edited August 26, 2017 by GT-R David

[KiwiRS4T]

How much did the 2.8 kit cost? Spend a few bucks more and get a Link or such like. Also are they old school Sards? If so get some modern injectors and double check the settings. Have you replaced the fuel pump...tested fuel pressure?

[GT-R David]

I actually like the Nistune and would like to keep it.

And they are not old school Sard, they are the new type with 6 hole for better spray pattern. P&P kit for rb26 engine.

 

We also tried a completly new basemap and it was the same. So no problem in the settings.

 

Fuel pressure is spot on, Greddy in car gauge shows no drop or rise in pressure.

 

 

[GT-R David]

Changed back to old Nismo injectors and problem is gone.

Still don't know exactly why...
Will have the new injectors get checked.