My Mates 200tdi starts but cuts out immediately unless the throttle is pressed. Once running it ticks over (maybe a bit rough but not serious) but when you rev it - it doesn't reach its full potential.
Bet its got an air leak somewhere in the fuel lines before the lift pump
They run fine just slightly down on power with a dead lift pump.
Simple thing is the throttle reaching the stop on the inj pump when pedal to the floor?