I know this has been done on the old forums a bit but I have an issue similar to the problem someone experienced before with the erratic idle, I thought i had fixed it will new vacuum hoses but to no avail.
My Problem is is that the thottle housing and all attached units is completely different to the starion manual (might have somthing to do with this now being a jap import motor, I have a spare thottle housing and bits etc. with the black circle ECI on the top but the one on the car is different.
Thats the second model of injection... Are you running that on the original JA computer? If you are, you might strike some over fueling problems as the injectors in the second style of injection are a bit bigger apparently.