BMW Repair: Engine Loping/Surging, oil leaks, throttle plate

Question
Hello Dan!  Just bought a 1983 528e with a manual transmission and 197,000 miles.  The car had been sitting for about 3 years when I bought the car.  I replaced the plugs, distributor cap and button, oil and filter.  Drained and replaced the anti-freeze. Removed the in-line (external) fuel pump and cleaned with Seafoam (works great now), blew out the fuel lines (have fuel flow-pressure?  Don't know).  The car starts up fine, idles great while its cold, but once it warms up...starts to "lope" "surge".  Could you please point me in the right direction to trouble shoot? Love the car...just can't get it to idle.  PS: Best car forum I have ever seen...you do the auto world a great service!!  Regards, Kevin

Answer
Well it is running that is a good sign.I don't know what you put for plugs in but the Bosch number is WR9LS.I know many others may fit but in BMW's the correct plug prevents future problems.Your surging maybe cause by the idle control valve being dirty or possibly being bad.If it is plastic it is original and probably due for replacement.When replacing the valve it is best to replace the control module as well.It is located in the glove box.Replacing both these parts assuming there are no oil leaks,valves adjusted correctly,throttle plate cleaned and the hoses not cracked or hard it should come back to a normal idle.