New to Audi's a4 power probs

[CalvinA4]

Hi I have a 1996 a4 1.9 90bhp , seems a little power dead like turbo isn't kicking in , I have gave the car a full service , but I have now took the turbo and inlet manifold off to clean or ports , I have all the intercooler pipes off and and trying to take off the intercooler but have had no luck , boost pipes are hanging off every where and I haven't a clue were to start with them and one have a diagram ? Can these cars be fitted with bigger turbo?