need help!!!

I recently purchased an 89' conquest tsi and I am having some problems with it and don't know for sure what to check next. I have replaced the valve cover gasket, rear main seal and water pump because I was having problems with them. When I took off the piping to the intercooler from the turbo it had a bunch of oil in it so I tried replacing the turbo but it is not fixing the problem.
The car wants to cut out when it is not hot. I have to rev it for a few mins after starting to get it to run. The turbo charger seems to be getting VERY hot VERY quickly. The boost gauge sits at -7 and when the turbo spools it will only go up to 0. There is also a lot of smoke that seems to be coming from the manifold. It gets heavier the longer it runs and I have only let it run like that for a min or two at most.
Has anyone else had this problem or know how to fix it? My friend and I thought it may be oil or fuel leaking into the exhaust manifold because we haven't fixed all the gaskets, but I don't want to rip the engine apart and replace them only to find out that they are not the problem. HELP ME PLEASE!!!

Clogged catalyst and/or bad pcv valve, plus maybe bad replacement turbo (seals) or a clogged turbo oil return hose (the big one from bottom of turbo to timing cover). Given no boost, I most suspect exhaust restriction (cat).