A/C Aircond RPM recovery

[R33Tech]

Not sure how to fix this, but when the A/C is running and the compressor automatically switches to off, the RPMs drop to almost stalling and hunt, finally recovering to normal. When the compressor is engaged, the RPM rises a little then goes back to normal.

[Matt]

Interesting one. Double check your FICD (fast idle control device) is clicking on/off with the air cond relay. I think it is, since RPMs are holding whilst AC compressor is on

I will note that you are running a bit lean at idle regardless (15.5 AFR on average). So you could try increasing latency a little, or increase min load a small amount (R33 is lower than R32 RB20DET) and see if that helps

Also noted from the log that AAC will drop from 49% to 29% momentarily , but ignition timing drops too(during idle)

Your idle target RPM table is less than factory values and may be responsible for this. I would suggest lifting the values back around 800rpm in this table too

[R33Tech]

Thanks Matt.
I tweaked the injection latency up a bit.
Lifted the Min Load by 1.
Set the idle to 825.
But the thing that made the most difference was lowering the AC on AAC duty from 19% to 7.5%. Now it only increases the RPM and decreases the RPM only slightly when going on and off.
Still a bit lean when the A/C is on though, at about 15.2. Running at about 14.3 when the A/C is off.

2024-10-31 19_52_17-Nistune [HCR32 SKYLINE (RB20DET) Feature Pack 1.0 (Version_ 4)].png

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