BMW: doesnt starts, temperature sensors, distributor cap

Question
hi if you can help me please whith this problem,because i cant fint the answer in my country.
I drive an E34 M20B20,the E30 type of engine,and i have the problem that the car doesnt start when hot outside.In the morning on the first key i don;t have any problem starting on the 1'st key,but in the middle of the day when it's hot outside the car doesnt starts,only on the 3'st key...
I changed the ignition coil,temperature sensor,filters but nothing,the same problem persist...
Please help me!!!
Thank you

Answer
Claudiu,
 Try changing the temperature sensors in the top of the thermostat housing, these go bad, and could be your problem.  Also make sure the engine has had all spark plugs, wires, distributor cap and rotor replaced in the last few years.  This will help quite a bit.

 Hope this helps,
 Josh