Hi, I signed up just for this one post, to maybe spare someone else some grief one day. Lets face it, these 1.6 tdcis are finicky and fragile.
Anyway, I just did my second ever DIY fuel filter replacement.
First time round, 2 years ago, it went without a hitch. Though I did notice, that I kept getting bubbles, no matter how long I bled with my vacuum pump. I kept catching it, and pouring it back in the fuel tank, at some point I felt I'd bled enough and decided these bubbles must have some other source, say the vacuum pump adapter. And it started right up. What did it solve this time round => the occasional complete cutting off of the engine, one time even on the highway. And it being down on power, though I did not notice this particular symptom as it was gradual.
Round 2, today, two years later. Same procedure. Again bubbles till the end, and I bled a whole litre. Started up. Nothing. Started about 5 more times. Nothing. Went online, watched two videos, picked up some useful tidbits of advice, like plugging the outlet from which I bled and filling the outlet pipe with diesel, to make extra sure there was no air, and priming the system by only turning on the ignition a few times before actually starting. Bled another litre. Started it up. Nothing!
Boy did I hate that engine at that moment, especially the designers. Then I remembered, last time I was being super cheapskatey and pouring the fuel back in the tank, which I didn't do this time on account of a dirty catch container, that had previously held brake fluid. So I opened the fuel tank cap, greeted by the usual whoosh of air. Bled again, though very little this time, and also plugged the outlet. Started it, it ran for a second and died. Started it again, and revved up to 3000, as I wasn't going to let it cut off again. And it was done. :) What a relief.
Took it for a test drive, and all was well again. What did it solve this time => no cutoffs, but seriously down on power. No usual turbo boost after a brief delay, it was as if the turbo was gone, it was that sluggish and down on power.
Moral of the story: don't give up, never surrender. Try everything. Maybe it was the fuel filler cap and the vacuum in the tank, maybe I tried one time too little to start it up. Who knows.