Hi to All, and hope somebody can help. My BMW was starting okay from cold but got harder to start when warm/hot until now which it cranks but does not start. I have checked all the relays and fuses which appear to be fine, I then located the fuel pump on the drivers side under the rear seat, and fitted a new check valve and while doing this put some fuel line from the check valve into a pop bottle turned on the ignition and diesel was filling the pop bottle with pressure so I assume no problems there. I then replaced the fuel filter under the car (passenger side), and still no start, but did notice that now the diesel fuel pump next to it is always priming every time you attempt to start the car, so replaced that and still no start but still constantly priming. A friend said it might be air in the fuel system with changing the filter etc, so he came over and removed the return pipe off one of the injectors while I turned the engine a few cranks, and diesel came spurting out under pressure, finally he sprayed some Easy start down the air inlet while I turned the engine and it started within about 4 cranks. So we let it warm up for about 30 minutes which it was running with no problems, however turned it off and attempted to start again, and back to square one, no start, started it again with easy start, let it run again for a while, then off, and again no start. Since then have tested the camshaft sensor with a voltmeter and appears to be working fine, that only leaves the crankshaft sensor which at the moment I can`t even locate never mind test, but got a funny feeling that is going to be fine as well. Just can`t understand why it wont start and the fuel pump is constantly priming. ANY Help would be much appreciated, Regards, Darrin.