mis firing diesel....

starts and idles clean and if you go easy on the throttle it seems ok but when you drive it normally it misfires like mad and wont rev thru it. the engine management light comes on as well when its missing, i have good fuel pressure at the filter (which is 2 weeks old maybe 600 miles) battery looks new but is only a 90ah one, any ideas??

Injector number 4 needle lift sensor, water in the fuel, bacterial growth in the fuel just for starters, really need to get the codes read.

tried to get the codes read at the local garage but their pooter wouldnt talk to my ecu..... any hoo i went back out and had a poke around the crank sensor and no4 inj (which i had recently changed) and guess what?? the bloody plug had come loose :dohlugged it back in properly this time and she's running smooth again