Hi, hoping somebody can advise on what is wrong here.

The best way I could describe it is that the engine 'misses' under wide open throttle. It's most noticeable around 2400rpm, but it can appear anywhere between 2000 and 4000 rpm.

Only had the Fabia 5 months, previous cars have all been NA petrol.

I was out playing on my local private test track and with my foot flat down and using the gears to keep it between 2400 and 2800rpm it was really bad.

When I first got the car the power delivery was nice and smooth with no issues like this.

Mis firing? Common problem is wiring looms in the head (120 quid to fix), fuel filter ruined maybe?

Mis firing?

yeah, it feels like a missfire to me.

On previous cars i'd be looking at plugs, ht leads, dispacks, etc but on a turbo diesel i'm not sure where to start.

I got myn scanned at a local vag specialist and they found the fault code ( mis fire cylinder 1 wiring loom). I'd go get it scanned if It were me mate, if u know some1 local with vagcom then they'll do it for u for a drink I'm sure

As DM has said, you need to get a scan to tell you exactly what and where the problem lies. No way round it I'm afraid :no:

well I didn't get it scanned because the problem disappeared as quick as it appeared.

The last 2-3 weeks the car has run fine.

Can this wiring loom fault be intermittant? or should I get it scanned anyway? Will the root cause of the problem from 3 weeks ago still be stored and be scannable?

Otherwise I was thinking a tankful of dodgy diesel might have been the source of the problem...

get it scanned. my Ibiza felt like it was misfiring quite a while ago and changing the fuel filter stopped it. more recently it was feeling like it was cutting out and shuddering really badly under any more than a light throttle, there were faults about injectors logged and changing the loom sorted it.

Mis firing? Common problem is wiring looms in the head (120 quid to fix), fuel filter ruined maybe?

wiring loom is like £50+delivery and can be done yourself. it's more annoying than it is difficult

just to update my original post,

After running fine for about a month the problem came back and wouldn't go away. It ran like crap everyday for a week.

I was going to change the fuel filter at the next service (80K) but due to the crap running decided to do it early. The new filter has fixed the problem.

Does anybody know if the date code on the filter is a 'manufacted on' date code or a 'use by' date code?