Idle issue with larger injectors

[Zever]

I've been running my 2007 350z with 850cc injectors for awhile now but I've never been able to get it to idle correctly after installing them. Its tries to, it idles down to 650 to 700 nice and smooth and then the timing will drop from 15 to 8 degrees and start to idle around 1000 rpms. The injectors work great and settle to about 1.8ms PW at 650rpms. It's almost like the ecu sees the injector PW vs airflow is out of parameter due to the smaller PW and it goes to a default mode with terrible low engine speed driveability. The multiplier is correct, offset is dead on and the scaler is right, after a little trial and error. It hits target AFR in open loop with every combo of load/rpm but something is not correct in the software with the idle circuit. I tried a richer afr idle target and it's a little better but nothing close to perfect. I've swapped the OEM 370cc injectors back in and it idles perfectly. Is there another table I shoud be adjusting to make something happier in the tune, maybe something with the throttles? Please if you have any ideas lmk. Thx, Ken

[SultanHassanMasTuning]

put your tune

with injectors like that you need to adjust several times

[Zever]

VQ37HR boosted 850cc injector latency.hpt21-12-22 17-56-44.hpl
I found a lot of good info regarding the multiplier, scaler, offset tables and how they effect theoretical IP. Been messing with it tonight and I realized I had the offset and scaler tables flipped as far as definition. It's much better now, I'm hitting the targets in OL now better then ever under low boost and it drives much better. The idle is better and I've got the TH IP much closer. Time consuming but not difficult now that I'm on the right track

[Zever]

If you know Nissan ECUs well and have any suggestions I'm listening, thx again

[SultanHassanMasTuning]

yes been tuning nissan for a long time
K-multiplier needs to be reduced with bigger injectors
you will need to rescale your theoPW tables (fuel and timing) for boost
latency
minimum inj PW

then you will work you maf for fine adjustments

[Zever]

I've done all that but the MAF tuning and it runs great except for an idle issue occasionally. I ended up using the stock MAF tables with the large intake tube so I'm guessing the ecu thinks there's too little air flow at idle and won't idle properly. I tried lowering the fuel multiplier and increasing MAF A and B tables by roughly 36% based on my estimate of increased intake tube volume as a start. After making equal adjustments to the tables my MAF voltages start to become very uneven at idle. So it runs great as it is with stock tables but that's where I'm stuck. I guess I'm doing something wrong, idk.