This is actually a continuation of my previous thread, decided to have a separate one. Anyway here it goes, basically got her just last week-1992 525i 5 speed (M50), was garaged for 4 months w/o starting, we only started her when we pick her up. Had a rough idle sound actually more like a misfiring from idle 'til 3,500 RPM, standing rev and moving. After 3,500 RPM as if nothing is wrong with it 'til 6,000 RPM.
Here's what I did:
1. Put new plugs
2. Bought 3 new ignition coil (As the previous owner says that it needs 2 igniter guess he meant coils upon testing found that it was 3).
3. Put new fuel filter, Fresh gas and injector cleaner.
4 Checked all the hoses & vacuum for leaks-found nothing everything is ok.

Results: for the few miles got a better idle and the misfiring like thing went down from idle to 2,000 RPM. As I used it today it went back to the same condition as when I got it. Rough idle at low RPM and misfiring like sound at high RPM. Planning to do today compression test.

I would appreciate any input at this point, thanks in advance!