I had the Z32 ecu nistuned for my car and always had idling problems mainly but no vct problems. IMO and my tuners opinion a 3L twin turbo V6 ecu simply doesn't work that well on a 2.5L single turbo inline 6 there is just too many variables. I since swapped to a Link G4 and the car idles perfect all the time and light throttle applications all seem so much smoother with the link