Help needed please!

[Flanders.]

I'll cut to the chase, the alarm on my Mk4 Fiesta went awol (I.e going off every two seconds) so I thought I'll unplug the battery and plug it back in again and it fixed it nicely. Now however the engine won't rev over 4k and its very lumpy and slow. Have I fked the ecu or something?

[Flanders.]

Bumpy bumped bump.

[Zad]

Disconnecting the battery can cause the engine management to lose it's stored settings. However, driving around for 5-10 minutes is usually enough for it to re-learn most of it. Clearly you have already tried this. It might be worth dropping the power again, just in case it has learned something incorrectly. I wonder if you disturbed something under the bonnet when you were checking around though, coil pack etc?

[Flanders.]

I think you may be onto something, as now its a bit lumpy until i get to the bottom of the road and then its perfect again, maybe the ecu hasn't learned how to run the engine right when its stone cold? As soon as its warm its fine again. Bloody car