I was performing a valve adjustment on my 89 325i using the diagnostic port to turn the engine over and I also disconnected the ignition coil wire to be safe and not start the engine with the valve cover off. I got the engine turned over to TDC (both lobes pointing down (180 degrees from rockers) on cylinder 1 and adjusted the valves and when I tightened it up and went to turn it over to do the next cylinder all I get a sort of tick and the engine does not turn over anymore. any ideas as to what might be wrong and how to fix it? thanks!