BMW Repair: 1987 bmw 325is stalls, 1987 bmw 325is, bmw 325is

Question
Thank you for your help in advance! 2 questions for you. I have a 1987 bmw 325is.  I can be driving the car and it will stall.  Sometimes it will start right back up however tonight I can not get it to start back up.  There is no spudder of the engin and the Tachometer drops immediately to 0.  When i try to start it does turn over but wont start.  Its almost as though it is dieing from not getting any gas.  The spark plugs have been changed recently.

#2 the speedometer and odometer do not work.  Sometimes they do and when it is not working if i drive over railroad tracks or some kind of bump the speedometer jumps as though it wants to work.  Could this be a bad speed sensor on the rear differential?
thanks again for you help!!

Answer
You need to check for spark and for fuel(fuel pressure)The connecter at the back of the cluster may be loose or you may need a new cluster.The sensor at the rear end is for speedometer.Check the conneter there as well it naybe corroded or soaked with water.