ive bought a 90 civic dx. someone has started a z6 swap and hacked up the harness. the car will start and run but has a ruff idle at around 500 rpm. it wont rev up past about 3 grand. i do know the iacv isent wired in. i also know that one of the 2 wires on it goes 20 a9 for the swap. but what about the other wire and will this fix the rev issues?