Mini r56 cooper s (N14) help
 

My min cooper s have a weird problem I can't figure out what so ever and I have spent alot on trying to fix it.

Car has a very slow crank but does turn over but only briefly then stalls, it has gotten a new high pressure fuel pump , low pressure fuel pump and filter , fuel sender, camshaft sensor, crankshaft sensor, fuel rail sensor, new battery, spark plugs.

Engine had a full rebuild 3 years ago, the engine is clean from carbon in all chambers, injectors are spraying correctly. I don't even know what to check next or try as I'm loosing hope on getting it running ever again.

It's been on the computer a few times and no codes showing up at all

Check the battery, most of the time its weak. Bad cell in the battery, check the battery cables also. Clean them and reinstall.

Tested the battery using a tester all seems good, checked the cables for corrosion but don't see anything to point towards it, don't think the car would start if that was the case tho

Weak battery will make it start but its slow to start, you need to load test the battery.