BMW E46 320d SE 2002 Poor starting from col...

Trying to start from cold takes alot of cranking, suspect lack of fuel, but not able to determine which fuel pump it could be. Once warm it's ok. AA started it once by squirting brake cleaner in the intake, diagnostic records low manifold fuel pressure and poor number 2 glow plug. No excessive black smoke when it finally does start. Propose to change the fuel filter and electric pump under the floor unless you can advise differently. All advise welcome.