Mercedes: 1990 300 SEL gasoline 6 cylinder, incorrect fuel, distributor cap

Question
idling rough initially..changed wires, injectors, distributor cap, fuel modulator.  Am now told I have incorrect fuel volume going to #2 cylinder.  Do not want to pay any more money for
repairs to not have problem rectified. I love the car.  

Answer
Why are you paying?
What you describe are all DIY items.
Please join: http://www.mercedesshop.com/shopforum/forumdisplay.php?f=1

There are many women on the forum who repair their own cars.

The issue could be:
#1. Bad injector, even new units can have a defect.
#2. Wire harness.
#3. Bad ECM.