BMW Repair: BMW 525i 1994 starting problems, fuel pressure gauge, bmw 525i

Question
I parked the car for 3 days because i've got a company car, and last night i wanted to go shoping when i got in my car and turn the key the starter went on, but the engine didn't start, its just spining and spining but it didn't start. I've checked the gas and it's ok.
Please help me with the problem. Thank you.

Answer
You say just spinning,is the starter turning the motor over and that is just spinning or is the starter just spinning?And also checking the gas..did you put a fuel pressure gauge on or is it just full of fuel?
These two questions I've asked are important for me to know.You need spark and fuel for ignition.Having the correct fuel pressure(about 3 bar)and spark(remove spark plug and ground to head,turn motor over and see if spark is present)