How do i change a 18 tddi diesel injector pump on a ford focus

You have to blled the pump as it has an air lock

change the oil and filter first if you can turn the motor by hand to make sure its not siezed. pull the plugs and put a little diesel in them put plugs back in . make sure your battery is good and crankit it a little to the oil moving through out the engine

Not enough oil pressure to open the injectors. Check pick up tube

sounds similar to the problems ive had with my focus tddi on several occasions due to the float in the tank sticking, so thinking i had more fuel then i actually did. if i were you to make sure fuel is being pumped, crack off injectors 1 and 4, then get someone to turnover the car while you wait to see if diesel squirts out from the injectors, hopefully it should fire, if it does get the person turning the vehicle over to stop, then tighten them back up.
i hope this helps, let me know

three simple start problems with diesels if you haven't ran out of fuel

1/ imobiliser not letting power to injection pump

2/ solinoid valve on injection pump

3/ starter motor

no you do not all the codes are in the ecm not the pump itself.

no, the fuel pumps are different in the focus.

There is leak in the fuel system and air is coming in somwhere. Maybe the hoses with the injectors are leak.

this is jason and in the caption above you said its a diesel right well nin diesel fuel there is a lot of water start by checking where the fuel filter is there shjould be a valve that can release water like on diesel trucks the light will come on and say theres to much water in fuel or whatever maybe that might be the case the sensors just might be reading water rather than fuel.