Volvo Repair: Mysterious Startup Problems, mass airflow meter, fuel pressure regulator

Question
I own a 1991 (or 92) 740 Turbo Wagon, automatic.

When I start the car in the morning or even if it has been sitting for an hour I find that it takes 5 or 7 seconds to get it running.  It turns over okay but the when it finally fires up, it runs super rich, like it is flooded. (puff of blackish fuel smelling exhaust)  After it leans out after the excess fuel is burnt off, it runs normal, although th fuel consumption seems to be poor.  The computer was checked out to be fine, the idle valve replaced, fuel pressure regulator new, new plugs cap rotor, new coolant temp sensor, and the mass airflow meter is supposedly working properly.  My mechanic does not think it is an injector problem but after all this and no explanation, i dont know what else to do!?

thanks for your reply............rog.  

Answer
Dear Rog...
          Hmmm...sounds a bit mysterous..
  Failed coldstart valve?
  Oxygen sensor..?
  Diminished spark...?
  vacuum operated system...with leak
  
    Finally....you should consider checking out spray pattern
  of injecters...although I agree with your mechanic....but ya never know...especially if the injecters are originals...

       Good luck
    Bilbo