help.t4 missing on start up

[GATHY]

help my cars starting to p@@S me right off.
my 2001 t4 started to miss when cold or been stood for a while for about 20 seconds on start up.so i got the code read and it came back misfire cylinder 3.
so i put in some new platinums for the second time this month last time for service.£45 doh >still misses.
so when and bought plug leads another 45+vat from dealers.>still misses
so when for the coil pack £50 from dealers and guess what it still misses.
any ideas ?
the cars only done 50k and just turned 4 all serviced up etc.
planning on setting fire to it and buying another vectra which always went wrong.i bought a volvo becaus ethey are reliable arent they ?
booo boo hhooo

[pikeajm]

could be the injector highly unlikley but could be check the conection to it

[GATHY]

cheers for that but i cant seem to pick my lip up of the floor yet
:+(

[rocket ron]

possible head gasket problem, missing on start is a classic symptom

[siamblue]

As above or a bent/sticky valve....