BMW Repair: tach not working, speed sensor, idle control valve

Question
1987 325i WBAAB5405H9808404  TACH NOT WORKING VERY HIGH IDLE. WHEN ACCELERATE CUTS OUT AND QUITS RUNNING IS THERE A TACH SENSOR ON FLYWHEEL? & WHERE IS IT.COULD IT B SPEED SENSOR WHERE IS IT. THANK YOU ARCHIE  

Answer
The tach is there to indicate engine rpm,it gets its reading from the negative side of the coil there is no sensor for the tach.The high idle could be a dirty idle control valve causing it to stick at a high idle,cleaning that might help.And as far as the cutting out I would check all the ignition components(plugs,cap,rotor,and wires)