i have a 87' 190e 2.3-16v and it got problems!

1) it wont keep idle...im told its the idle compensator?
2) on idle the damn thing just runs extremely rich and has no top end power. i just gave it a tune up and a plug change...no good. they tell me it is the fuel pressure regulator??!!

whats up with this?! Ive taken it to 3 mech and each has a different answer. i got this feeling im being taken for a ride..,oh the joy of having a benz...!

Any help you guys can give is deffinetly usefull since in this close to selling the damn thing even though i love my 1st car.
thanks