TD4 Turning Over But Not Starting

A couple of days ago while driving up hill the engine management light came on the car seemed to loose power and smoke heavily. Once I hit level ground the car seemed to correct itself. The next morning the car turned over along time before starting it did this for for the next couple of morning and then today it just turned over without firing. Hopefully someone could point me in the right direction of what the problem could be. It’s a 06 plate with 134k on the clock.

Check the lift pump is running. You should hear it from under the HRS rear arch.
The high pressure fuel pump regulator O rings can crack causing starting issues.
The rail pressure sensor wiring can corrode causing odd running issues.

I sprayed a bit of easy start down the air intake on mine, it started and ran fine but would never start again once stopped. It was faulty injectors causing my problem. Hope this helps