I just got a Z32 with a S2 RB25DET. It is a stock motor with the factory s2 ecu. rb25 maf. MAF, Turbo, plugs, fuel pump and IACV have all been replaced. The idle bounces up and down. I have only drove it around the block once.
Here is a video of what it is doing. If you can help me figure this out, I'll paypal you $1!
RBZ32 start up - YouTube