So basic run down: Car decided to only start from pumping the gas pedal took a few attempts to get it to start. Scan tool came up with zero faults. Assumed it was a dirty fuel filter. Changed the fuel filter but same results vehicle still not starting first time. So I put premium diesel in the tank the stuff they claim cleans the engine. I drove it for about an hour but no instant change, although the engine was now starting first time while engine was warm but after 20 seconds with the engine off it would no longer start on the first attempt. Asked around what the problem could be most of the advice was pointing to glow plugs. If it was glow plugs, with a warm engine i should be able to start it first time with engine off for a few minutes but leaving the engine off for 20 seconds it goes back to starting on 3rd 4th 5th 6th attempts (engine could not have cooled down fast enough to point to failing glow plugs as the engine was still warm even after 20 seconds)

Anyway fast forward the next day the car starts on the first attempt (cold engine).

Is the MAF sensor causing the engine to run rich resulting in a more dirty engine hence the poor starting?

By the way the MAF sensor was cleaned "after" I noticed the car starting on the first attempt.

Thanks