I have a BMW 745i %2Cit has an issue cranking %2Cit turns over for a while before it starts and theres no set pattern or time limit sometimes it starts right up and other times it takes a while %2Cwhat do you guys think the issue may be%3F

The issue may be that you have not been keeping up on your maintenance- the issue may be that you have not been taking it to a qualified BMW specialist when problems first pop up- your car is a VERY complex piece of machinery- and needs to be supported with a cash sacrifice- the Guru says to prepare yourself for the ceremony of the Golden Cash

Could be a issue with your fuel pump needing to build up pressure to start the engine. It's called bleeding back. The pump when shut off has a check valve built in to keep the fuel lines primed. When the valve fails it will allow the fuel to bleed back into the tank. The pump then will have to build up fuel pressure when cranking the car. To know if this is the correct issue you will need to check the fuel pressure after letting the car set and when the long crank happens to see what fuel pressure is at should be around 5 bar.