My Car chokes......

I have a 1993 940 Turbo........I dont know what is going on with my car but I do know that it starts to choke and/or is not getting enough gas to the engine when I first start it up and put it into gear and even sometimes (now more frequently) while I am driving........ I had the throttle body gasket replaced, the fuel filter replaced (but I think the guy did a whack job), I put a complete fuel system cleaning formula in it, and a tune up. I dont know what it could be, could it be the turbo going bad in my car or could it be the faulty fuel filter? Could someone with some expertise help me out?

Thank You,
Jay