Bnr34 positive boost lean issue

Hello there!

I am using a link plug and play ecu on my daily use Bnr34 with an rb26 engine car runes almost great on idling and cursing area while using alpha in (TP) as loud Vs rpm. During a dyno run on positive boost pressure afr ratio jumps extremely lean I tried to fix the issue by using the 4d table load (map Vs rpm) by increasing the fuel % on positive boost pressure but still the changes did not make any difference. I thought of installing a fuel regulator to know if there arnt any droop on the fuel pressure. Car is completely stock ,

Stock 444cc denso injectors.

Please I would appreciate it if you could have a look on my map to see if I'm missing something and I will also add my data logging that I did on positive boost .

Best regards

Hi Mohamed, the problem you have is that you have set the axis for the open loop AFR table to 'MAP Sensor Volts' instead of the parameter MAP. This means that your AFR target is always staying at 14.7:1. Change the axis parameter to MAP and you should be good to go.

You may also find that the fuel pump speed control is not effective as it is currently setup. For some reason we had trouble with the default setup which had the last car we tuned go lean at higher rpm. We ended up bypassing the speed control system and wired the pump through a relay but if you're still having difficulty with the fuelling at higher rpm/high boost, this may be your culprit. You can set the FP Speed output to 'Test (on)' or OFF and one of those options essentially runs the pump at full speed all the time. I'm sorry but I can't recall which it was.

Thanks Andre!, I had found the issue that made the AFR droop lean at high rpm and fixed it !

FUEL PUMP CONTROL

SPEED CONTROL METHOD 80HZ 33/66/100% DC

FP LOW - MED= 20%

FP MED - HIGH= 80%

In this set up it worked perfectly for our AFR TARGETS