I don't know much about E30, but we have several knowledgeable members in that area. Try posting about your issues in the E30 tech section
for better chances of getting a pertinent, useful response. Also, I recommened that you get the Bentley Repair manual for your car. In general, Bentley writes much better manuals than Haynes does for BMWs. You should be able to get it at Amazon.com, generally with free shipping.
Lastly, I commend you for first reading the FAQ and tech threads.