Small niggle with WS engine

[doctamick]

Hey All,

The last few times I have driven my car, I have noticed that the engine runs a little rough when cruising in fifth gear at about 60-65 km/h. It feels as though there is a slight misfire under light loads at this low rpm range (approx 2000 rpm). It seems to only occur when the engine is cold, and does not happen after 5-10 minutes of driving.

I wonder if there is some build up on the plugs. I usually do primarily long drives from Melbourne to Geelong, however in the last couple of weeks I have been doing many short trips of only approximately 10 minutes. So maybe the engine is running rich during most of this period (due to cold start settings) and does not have time to burn off any carbon deposits on the plugs?

I am not sure if this is related to the stalling / flat spot problem described in this post: http://www.fordforums.com.au/showthr...8&page=1&pp=25

The car is a manual WS Fiesta Zetec and has done 13,500km. So it hasn't had its first 'real' service. Did anyone with a manual car get an ECU update on any of their services? (I know that there was one for the auto.)

Any of your experiences would be great, as it will provide me with more 'ammunition' when I speak to the dealer about it at the 15k service.