starts but won,t run

[beechnuts]

help i have a 1988 230e with k jetronic fuel injection.the car starts ticks over for a few seconds then cuts out it will not run.i fitted a new fuel pump no differance,the fuel relay seems to be working i can hear it kick in when the ignition is turned on,fuel is being pumped to the base of the distribution head but doesn,t come out of the injectors this is a reconditioned unit so should be ok. any ideas please