Hello,
I have been admiring the progress done by you in the overhauling of, ehm, almost everything in your FSI engine. As a fellow FSI owner who has already changed most parts in my own 2002 FSI (affectionately known in my household as TMP, or The Money Pit?) I admire the thoroughness of your job and the determination in going to the roots of the problem. FSIs can be tricky if maintenance in the past has not been good
I have not the time nor the skills to do the jobs myself but I trust my garage (they restored all my classic cars from a 1949 MM to a 2005 XJR) and they did almost the same work as you did, changing injectors, vacuum actuator, throttle body, sensors et al. To be honest I picked up a lemon as this FSI looked good but it was actually a mess! Now the FSI works passably well but it still feels a bit rough so I'm ordering the Denso plugs, as you did feel an improvement with these, and see what happens. The pump was already checked by a specialist and declared OK but mine is a 80,000 miles car so I expected it to be good.
Well, it has been a long rocky trip but you know what? The FSI feels good. I own also a 2000 Porsche Carrera 4 (996) and there is something of that engine, with its VarioRam action, in the FSI behaviour (though I must say that the FSI has been more expensive for me until now ? ).
I think that we all love our A2s (our household has three of them) and that all of us think that A2s are instant classics, but while the survival of the TDI is endangered by 'green' laws and limitations, and the 1.4 are a bit slow and also a bit 'normal' (delightful to drive, though, my wife LOVES her 1.4) the FSI will enjoy a higher status in the future and thus become a true collectable. Plus it's a hoot to drive.
Congratulations again for your splendid job! Can't wait to receive the Denso plugs to see how my FSI changes.
All the best to this splendid Club and Forum,
Stefano