My brother has just refitted his 1.8 ZVH into his FRST and it ticks over at 4000rpm. We have checked for air leaks and cant find any. It has a super chip plugged in the bottom of the ecu and when this is removed still idles at 4000rpm but when the chip is wiggled in certain positions it idles around 1000rpm but sounds like its running rough. The idle control valve has been changed and that made no difference. I am thinking it maybe something within the ecu/chip? Any one got any ideas?