psicks

I blew the stock AST apart in my '92 RHD awhile ago, it did not explode but it was leaking coolant from the horizontal seam around the middle of it; so I parked the car until the new AST (petit brand) arrived then did a coolant flush and replaced the AST. The car seemed to run fine for a few weeks but I was not driving it much then I noticed a small oil leak under the car on the front right hand side (drivers on my car) about where the turbos sit, the car also spits out some nasty smoke that makes my eyes burn, doesnt smell like coolant and its black/grey in color. The car has also stalled once or twice on me but only right after starting the car from cold and only when I came to a full stop.

The car is entirely stock with the exception of the new AST, im looking for some suggestions as to how I could possibly trouble shoot this?