I have a 1990 xj with the 2.5l engine. the miss firing came along when i was driving out of no where. been trying to figure it out for a week or so now and havent had much luck. when i start it it wants to almost die but doesn't. when revved up it runs rough up to about 2k rpm then evens out. any help on this will be much appreciated.

things ive replaced:
coil pack
cap and rotor fairly new
sparkplug wires fairly new
plugs new
cps
fuel filter

Any vacuum leaks, esp. around the MAP sensor?

im thinking probably i pretty much got it in rough shape but have been driving it and going through trailish areas and it just recently came out of no where running like this

Just redid compression test all cylinders around 150 plugs are black

Probably running way too rich. Did you check the MAP sensor and vacuum lines to it?