What is this metal hose on my coupe

[IHK 11]

Hi i have a 1993 Audi coupe 2.3e which i bought 3 years ago but has been off the road for 13 years altogether. When i bought this car i got it running after a friend fixed the immobiliser but then it stalled and wouldnt run again. I found the issue to be the distributor and since getting a new one it has a great spark. The car sparks well but still wont start although the local garage have had it running on easystart but thats not ideal. Today we took some stuff off to try and get to the injectors and also found a split on the underside of the metreing head rubber boot. Anyway theres a metal pipe that goes from the underneath of the metreing boot to what looks like the engine. We removed this metal pipe which we believe to be a breather hose and it was totally clogged with what looks like mud and grease. Even water couldnt flow through it. Weve soaked this pipe in all sorts of cleaners and its totally clear now but when we looked into the hole by the engine where this pipe goes into the hole was full of what looks like black grease. Do you think this is oil gone bad as the cars been stood for so long. Does anyone have any idea if this could be a reason for the car not running? Either way this looks like a problem that needs fixing. Any ideas about this and how it should look? Any advice or knowledge would be really helpful. Thanks everyone. Could this even be part of the air coming into the car and effect the heater? Thanks.this is the hole the metal pipe goes into from the metreing rubber boot.