Hi I am new to this club but I was on the "BMW Digest" years ago.
We now have a '94 318i auto (100k mi) which overheated when the top plastic radiator hose flange broke and instructions to driver about watching temp gage were misinterpreted, after fixing and refilling coolant it seamed to be not running on #1 cylinder (pulling plug wire caused no change in idle). Based in pervious experience, I (mistakenly) assumed bad head gasket or valve. I bought gasket set and head bolts then pulled head ( a PITA job took 3x longer than on my old '84 318 / m10) and found everything good (valves, valve seats, head gasket, head flatness, cam lobes, etc), cleaned head, top of pistons, intake manifold and reassembled, replaced oil and coolant and it started right up with #1 showing the same symptoms. Upon further investigation found #1 was (at least at idle ) running too rich to fire. #1 injector looked good when I had head off. Have not tried switching injectors yet. Coolant temp sensor for ECM reads good per ohmmeter. After sitting off for 5 minuets fuel rail still held pressure. Any Ideas? TIA, David