I have a problem, My 92 tsi is running on just 3 cylinders. I replaced the plugs, then replaced the wires, then the coil...still 3 cylinders. When i pull one of the wires off the plug while it's running it doesn't change the sound or how it's running at all, which led me to beleive that it was a spark issue. Now, just for fun I pulled that same wire again, stuck in an old spark plug, started the car and lots of spark was comming off that plug. So now I think it's fuel, a bad injector maybe, but even if that is the case, why doesn't it sound different when I pull that plug wire off?? Unless there is absolutly no fuel at all coming from that injector. Can an Injector completly stop spitting fuel??

If it's plugged, yes.

Do you have a datalogger? You could try turning off that injector specifically. Other option is to pull the injector.

Compression Test, Could be a burnt Valve

Have you confirmed that the injector is getting the signal to "fire" from the ECU?

Also, check the resistance of the injector coil. If memory serves, it should be something like 33 Ohms.

well, I tried a couple of things... replaced the ECU and Injectors. Still the same thing. Next I guess is a compression test??

It should be one or the other.

1.Check to see if injector is getting signal from ECU.
2.Check compression.

50/50 chance

My thought, from personal experience as I had the exact same issue with my 93, it intake gasket!

I had the exact same problem to the T.

Found a missing bolt on my intake manifold, and it had blown out that part of the gasket.