Hard starting 300tdi.

Hy guys, recently replaced the lift pump and cleaned the fuel tank out. Rrplaced the wee hoses accross the injectors. Now she takes a bit of cranking before it fires up. I think fuel is seeping back down into tank when parked for a while.
Any ideas? Anyone fotted a non return valve to the fuel line?

Check the lift pump, there are some rubbish ones out there. And check pump connections.
I have a clear section of tube in the feed line just before the lift pump to check for air bubbles going either way after problems in the past.
Fitting a one way valve may just hide a problem for a while until it gets worse.

make sure the leak off pipes are the length they should be and of decent quality and are your earths all clean and pucker and lastly check that solenoid