Hello to all.

I am newbie, though have looked on this site many times as i know there are a lot of knowledgable people on here.

I now find myself in a position where i need a bit of guidance so i thought i would try on here 1st.

Came back today from a weeks holiday and decided to take car out. Found the battery was flat so jump started it.
Not unusual as the car does not like to sit for very long and this has happened a few times in the 3 years i have had the RS.
It started easily and i left it ticking over for a while as i put the leads away. Started driving the car and noticed the battery light was on, decided to turn round and go home as i did not think the car would restart if i pulled over to have a look.
Then the car started to run rough so i limped back home, only 400 yards or so.
Got car on the drive and checked everything over, all looked ok. Started the car up again, battery light had gone out. Though the car was still missing, pulled each lead and found that it wasn't firing on No2. So i changed plug, no difference. Changed lead, no difference. Changed coilpack, it ran smooth as silk . Took car out for drive, got about as far as before and it began to run rough again .

Now i have two focus's (mine and the wifes, who's car i nicked the bits off to do the tests) with coilpacks that are useless on No2!

If anyone has an idea as to what might cause this i would be grateful to get to the root of the problem.

Also puzzlingly, although the car ran for very short periods of time, not enough to put any real charge into the battery. It started every time i needed it to. At least 8 times with no further need to jump it!