If you've bled the fuel filter
I would bleed again at the 2 small bleed screws on the fuel pump
, bleed the bottom one 1st until fuel runs clear, then the upper one. Crack the injector lines on cylinders 2 & 3. When you turn the key to start it make sure the throttle is in the fully open position. Once it starts to fire reduce the throttle setting and tighten the injectors lines.
I changed filter head
from a CAV sandwich type filter to a spin-on filter head
and a nifty little hand pump sold as an extra that's very easily fitted at the filter head with 2 longer banjo bolts and saves the contortions and sore fingers on Perkins
standard arrangement, it's not expensive and you can find it at A.S.A.P Supplies.com
if you are changing the fuel filter with the modified spin-on set up you simply run the engine for 5 mins, stop it, remove the spin-on filter, fill the new filter with fuel, and screw on, start the engine on tickover and it may hunt once or twice but generally with a little practice/experience you don't need to bleed the fuel system.
I hope this helpful to you.