I had posted my problems back in Sept. 09 and thank you for all the info, but still have a problem. I have a 1990 740, 4 cyl, non turbo, 277,000 miles, regina system. New wires, cap, have replaced some vacum lines, cleaned back of coil and cleaned IAC valve. Car ran much better after cleaning valve, now even slight dampness car starts hard. If it rains and sete overnite I really have to crank on it to start. And it will backfire a bit, shakes a lot and will run, but very rough. After warm up and driving sometimes it idles fine and other times it idles with a surge. Has plenty of power on the road. Also hooked up a plug and grounded it, had a orange spark to it. Also the temp gague on the dash does not work.

Thanks a lot.