Very trying Triton

Hello all,
A guy I work with has a 2002 model Mitsubishi Triton 2.8L diesel (NON TURBO) with about 230,000kms on the dial.

He is experiencing problems when starting from cold. Once the engine has been run for the day, the car starts fine. However, on the first start up of the day, it has to be cranked excessively before the engine fires up and he has also noticed some blueish/grey smoke coming out of the exhaust.

In addition, he's also noticed a lack of power.

One person suggested a glow plug problem(?), although given the dramas some other mates of mine have had with Delica's and the similarity of the symptoms, I was thinking more along the lines of injector pump, more specifically bleed back.

Any ideas????????

Thanks in advance....Fab.