I recently put up a post about engine running problems, someone suggested replacing the Oil Pump, its a B230F with 250K so it would seem like at this point wather its bad or not it should be replaced just in case, though i have a few questions here,

1 What are the symtoms people have exp when there pumps were dieing?
2 is there and easier way other then what the F&Q suggests to do this? or has anyone done it differently?

My car currently has a serious mechanical problem, which is not related to any ignition or like sensors or motors which have all been replaced. I was going to shim the valves thinking they were way out of adjustment. Would it seem more realistic to replace the oil pump first and see how it runs after word.

THESE ARE THE PREVIOUS SYMTOMS THAT HAVE ME ON THIS GOOSE CHASE OF REPLACING PARTS

Vibration at idle big time, noise from under valve cover at around 1200-1300 rpms i would say it sounds like a low pitch whistle, starts like crap in the mornings, the car never dies just starts like crap, about 10k ago it would crank over and fly up to 900 and just sit there and warm up, now it puts it way up there and waves all over the place wather cold of not. Before replacing all new items engine would be running and act like a miss hard, tach would follow this, now it somewhat does this but not nearly as bad and i think its because of the center support bearing needing replaced.

For the sake of it ill list whats new on the car so i can get a proper guess here.

New Items

Distributer
IAC Motor
ECU
ECT
T Belt
Harmonic balancer
Flame Trap
Fuel Pressure Regulator
Fuel Pump & Filter ( In Tank Pump Working )
Power Stage
Ignition Relay
Knock Sensor
o2 Sensor