Rough Idle - Fault 1213 - 1994 740i

I checked under the hood and noticed that the air intake hose had loosened and the cooling fan had chewed right through the hose. I don't know how long the air leak through the hose had occured. I sealed it up; however, the rough idle continues with Fault Code 1213. Thinking that plastic residue from the chewing of the hose went through the engine and idle speed control valve, I thought there may be a problem with the idle speed control valve and did a resistance check on the valve. The resistence is about half of the 20 and 40 that it should be.

It has been getting cooler here in S. Calif, and when I started the engine after cleaning the mechanical part of the idle speed control valve, it ran well for a minute or two, then the engine went back into rough idle. Depressing the gas pedal doesn't help. I started the AC and put the vehicle in gear and the rough idle doesn't change. Any suggestions?