So my dad was working on his MR2 and he's been fixing a lot of things, because ever since he got the head fixed, a whole lot of other things started going wrong and it's been running pretty rough. But it's started improving a lot. Just the other day he told me there was a 5th fuel injector that goes to the intake manifold. It doesn't have any power at idle, and he thinks it's bad, but first he wants to know when exactly it's supposed to kick in. More specifically, at what RPM range is it supposed to work? Any help is appreciated.
