1996 A4 TDI SE

[The Sandman]

I have problem with my A4.
When I bought it the car developed a problem when I was up at speed the car would lose a bit of power etc...
It was as if the brakes were coming on a bit and slowing the car down.
I checked the brakes and the offside rear pads were worn down to nothing.
I took it to a mate of mine who told me I needed a caliper.
i had a look at the old caliper and it was totally humped.
I got a caliper and new pads etc.
After this the car was going a lot better.
It was due a service and a timing belt. I got both of these done. I also changed the tensioners etc...
Now there seems to be a lot of black smoke coming from the engine at low revs and sometimes when in 5th gear and cruising at 60-70mph.
I have also had a loss of power when at 60-70mph when going uphill.
It is as if the turbo is not kicking in.
Anyone else had these problems or does anyone know anything about them ?
Any help would be appreciated.

[nickasaki]

Check to see if your car is a fly by wire set up (no throttle cable ) if so then there is a good chance that the pump timing is out ,if this is not the case the third fuel injector has a electric plug on it ,either the plug is undone,faulty or the injector is faulty , this injector is the control injector for the others and it might be sending incorrect signals to the brain causing overfueling this gives the symptoms that you have...Good luck