FSI Engines - Injector, coil pack and carbon build-up issues

[Phunked]

I own a 2008 MKV Golf 2.0FSI Pacific with 110,000 kms on the clock, and I've had intermittent misfires over the last few weeks. I've owned the car from new, and had it routinely serviced at South Yarra VW until its 60,000 km service, but at a local mechanic since then. All servicing has been as per the VW schedule, and I had the fuel injection system "High Pressure" cleaned by south Yarra VW at 60,000 km (approx $350 from memory). For the first 90,000 km, I nearly always used Vortex 98, but since then I've mostly used Vortex 95.
The misfire would usually happen in 3rd gear, under load, at 1,500 - 2,000 rpm. When the misfire first occurred, my mechanic found a code for misfire in No. 3 cylinder, and replaced the coil pack after inspection. A week later, the misfire returned. This time my mechanic got codes for multiple misfires, so they replaced all of the plugs. A week later, the misfire returned. My usual mechanic was booked solid, so I took it to a VW speciallist where they initially replaced all of the coil packs, but that didn't fix it. They then identified a fuel injector fault, so they replaced the No. 3 fuel injector (all up around $1,000).
I've had a look around various forums and there appear to be a significant number of FSI engines (VW & Audi) with fuel injector and carbon build up issues. Firstly, I'm pissed off that the fuel injection "Cleaning" at 60,000 km didn't prevent this issue (I guess they saw me coming), but I'm now concerned that it will happen with the other injectors, and there's also the possibility of having to remedy carbon build-up at the inlet manifold and on the valves.
I love my Golf, but I want to know how likely it is that I'll have to shell out for more injectors and carbon cleaning in the near future.

[Transporter]

Intake system cleaning should really be done every 30,000km at least, if you don't want to have much of the carbon build up. It will also depend what chemicals are used. I'm using the BG system and am happy with the results.

It's also important when dealing with the missfire, that it's properly diagnosed before replacing any components.

[Bug_racer]

Intake clean wont clean the injector tips which basically get carbon build up on them causing spray pattern issues .
I dont care what anyone else says , the only way to clean the intake is to physically remove the intake manifold and clean it by hand ! There is no real preventative maintenance !

[Fixxxer]

If you havent already, get someone to load test your battery, especially if you are on your original battery.

[Phunked]

Thanks for the replies.
I'm already on a replacement battery - orignal died 2 years ago >_<

Engine seems fine now. I haven't had it carbon cleaned (yet), but I'm wondering if that's going to be necessary soon.
Has anyone else had similar issues?

Cheers.

[bennjamin]

I'd be keen for a DIY carbon clean...102k on my fsi and in sure it's full of gunk !