I recently picked up a nice '84 242 (M46) that sat more than it was driven. (33K) Engine was real rough when I got it but have since replaced the plugs, cap and rotor, air and fuel filters, (all originals). I cleaned the throttle body, checked timing and have put a couple of hundred miles on the car and it is running good but with a few issues. I've read the previous posts about cleaning the Idle Air Control Valve and will check that today. However, I'm not sure about one thing. The idle does lower when I ground the Bl/Wh pigtail but even closing the black plastic wheel on the TB down all the way, (still 3-4 threads showing, normal?) I can't get the idle lower than say 900-1000 RPM. Of course un-gounded the idle rises a lot. This makes me think that the IAC is working or am I missing something? Maybe it's working but not fully? (stuck) Car is also hard to start and rough when cold and then runs smooth when warm. A high idle is particularly annoying with a manual trans.