Misfire / Plugs

[agent006]

I'm getting a nasty misfire for about 30 seconds after a cold start on my audi. Also get the occasional hesitation just under 3000rpm. Would i be right to assume that the plugs need doing?

[pdV6]

Would have thought that the hesitation was more a fuelling problem. The fact that the misfire comes in at a regular time from cold may be a clue - is the ECU changing over from its "cold start" to "hot running" parameters just about then?

If investigating plugs, don't overlook leads as well. Depending on what type they are, they can crack internally.

[pdV6]

Meant to add... could be something silly like the mass airflow meter or lambda probe etc that gets ignored when cold but is telling the ECU porkies when hot.

[agent006]

I'll add that it's nearly 6k miles overdue a service, in case that makes a difference. It'll get one next week but just wondering how big a service to get done.