BMW Repair: engine miss fire, 1984 bmw 733i, bmw 733i

Question
I was just givin a 1984 BMW 733i 6 cyl. the car has a rough idle i checked plugs cap rotor and compression. all cylindars are@ 150 psi even. # 6 cylindar fails the drop test i also checked injector with a noid tester and it has a normal sound coming from it. I am an automotive Mechanic asswell just not very familiar with bmw's please send some advise. thanks in advance.

Answer
The car has a rough idle and #6 fails a drop test(what is that?)?Have you checked the fuel pressure?By checking with the noid tester what happened?A noid test doesn't make a sound it goes by the light emitted.I think also you should use spell check when sending your reply.