Misfire at cold starting, 2003 S-type 2,5l

[Stale Mathisen]

Hi,

I have a 2003 S-type 2.5l, 150,000km. When cold starting, the engine starts fine and the rpm is around 1,500rpm. After a few seconds, when the rpm starts to drop, the engine starts to run very rough, and the engine light starts to come on, sometimes flashing. After a few more seconds, when the rpm reaches around 1,000rpm, the engine runs fine again, which it then continues to do while driving. The error code is ''misfire cylinder 1 -3 -5''. I suspected that it could be a vacuum leak, and replaced all the gaskets on the intake. I also replaced the plugs and coils, but none of this has helped. Does anyone have an idea what could be wrong?

[LairdScooby]

I'd read the DTCs first before you fire the parts cannon at it. It sounds like the whole bank is effected so i'd look more at a fuel delivery/pressure problem on that bank and as a general bit of maintenance, run some injector cleaner through it.