BMW Repair: 1987 BMW 325i, Difficult Engine Warmup, air fuel mixture, coolant temp

Question
1987, BMW 325i, engine starts easily but will not take throttle when cold.  Either I have to drive the vehicle at a low speed with very little throttle or really put my foot into it to get it to move down the road.  Engine idle is slightly rough. Once warmed up the engine performance is rather good inspite of the 257,000 miles on the odometer.  From time to time, the "Check Engine" will light when running down the highway with engine warm and runing well.  Recently a mechanic replaced spark plugs, cap, rotor and oxygen sensor to fix the problem.  The work done did not eliminate the problem at all.  I took the vehicle to a BMW dealer who did a basic check of the engine for vaccuum leaks, etc.  They wanted to start other work such as compression test, fuel pressure test, valve adjustment, etc. for $400-$500. I told them to stop as I found it hard to believe that those items were associated with my warmup problem.  I would appreciate any suggestions as what the problem maybe.
Thanks,
Bob  

Answer
Have you checked the coolant temp sensor? airflow meter?
a problem that is specific to the warm up period suggests a bad sensor that it causeing a bad air/fuel mixture during warmup.  I'm quite suprised the dealership didn't put it on a 5 gas analizer to see if it is running rich or lean during warmu; have that done if you can.
definately check the coolant temp sensor, it's most likely the culprit.
-cheers