Oldsmobile/Buick Repair: 1988 skylark runs rough., mass air flow sensor, mass air flow

Question
I have a 1988 Buick skylark with the 3.0L engine; the engine runs rough.  I have replaced spark plugs, plug wires, coil pack, control module, crank sensor and mass air flow sensor.
The car has good power just runs rough.  When I pulled the plugs they were all clean with a nice white look to the end.  I got the car with 32,000 on it; it now has 97,000, but has always been a bit rough.  I have also replaced motor and transmission mounts they were shoot. Also, no warning lights or codes.

Do you think it could be the fuel injectors, oxygen sensors, or something else?  

Answer
Hello Russ,
I would check for vacuum leaks....even to the point of connecting a vacuum guage.
A dirty or sticking EGR valva could cause enough leak to idle terribly, as could a leak in the power brake booster, and a/c controls if they are vacuum operated.

Van