E60 N47 crank no start

[Jackmorgan161]

Hello,
My car is not starting after replacing the timing chain kit
It used to crank and not start
Now after replacing the glow plugs and glow plug module it cranks and coughs out smoke, the rpms jump up when smoke is blown out.
I recently replaced the crankshaft sensor as i was told it could be the cause of the jumpy rpms but no help.
What could be the problem?
Fuel is present
Pressure is good
Battery is on charger

I think it would be something electric as the car only cranks for about 5 turns for a duration of 5-6 seconds then cuts out and lets me repeat the crank.
Help
THANK YOU