A friend of mine has a 92 525i that has developed a problem with the engine running bad (misfiring) passing thru 3100 rpm and just cuts out completely at 4000 rpm. (It runs smooth other than at those rpm ranges.) It has been sitting for some time because the tranny needed work, but did not have this problem before. Trans work was just a pan seal and low on fluid--car is shifting fine now as long as you don't hit 4000 rpm accelerating. Any ideas?