I have a 1984 BMW 325e that I've put tons of effort into, rebuilding the top end since it had been sitting for over 2 years. The problem is a miss in cylinder 5 at idle until about 1000 rpm where it begins to disappear. It has a refurbished head, just adjusted valves, injector is working, I have plenty of spark, I've ran out of things to try! I compression tested it and the compression came out to about 80 while the other cylinders were at about 135. I adjusted the valves which helped but it still misses at idle, although sometimes there isn't much of one at all where it's maybe the tiniest rumble or nothing to about to stall. I can't think of anything wrong on the bottom end that wouldn't just be a total loss of compression and power. When I run alongside my friend's 325es I can keep up no problem when above 1000 rpm and his car is running at 100%. I've done the IAC valve, my AFM wouldn't cause a single cylinder problem, nor would vacuum lines. I even moved around injectors after cleaning them and still the problem is only at number 5. Any ideas would be appreciated, I'm just at the end of my rope.