97 540i engine missfire

i have a 97 540i. bought the car for 1200 bucks and didnt run. car sat for a while before i bought it. replaced the fuel pump and got it running but there is a major engine miss. i just replaced all the ignition coils along with plugs and still have the miss fire. it barely idles but when you give it full throttle it seems to smooth out a bit. not sure if it would be injectors or not. if so how do you test them? or if you know any other things that would cause this let me know. mabey a bad sensor? if you can help i would greatly appreciate it.

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there was also oil in the spark plug wells probably due to leaking vlave cover gaskets

97 540i engine missfire