Here's a good one:

3 weeks ago, my 1990 740 NA car had a no start problem. After giving it a good try, I finally caved in and had it towed to a shop. THe mechanic wnt through everything, and I mean everything. As it turns out, the RPM sensor I replaced when the car was in my custody was defective. strange, since I tested it a couple times after I put it in. I guess the mechanics o-scope is better than my multimeter. at one point we thought it was the computer, and it was replaced with a used one. anyhow, issue resolved, car starts fine.

Enough rambling, here's the new issue: (all of this has happened in the last two weeks)

Rough idle:

Idles around 900 when not in gear, in gear idles between 775 and 650. searches a little, seems to be "missing". I went over all vaccuum and electrical connections, all look OK. haven't looked at TPS or cleaned TB yet. I see bad stories about that. Ignition OK, all was replaced from the power stage on. Don't know how to check timing. Could there be a valve timing issue? Idle was fine before no start work. has been getting worse progressively.

Exhaust:

Got pretty leaky and loud all the sudden, I want to just replace everything from the cat back. I've been looking into performance exhaust, since it seems to help NA cars, but I don't want a loud car. what are some good options, as I'll do the work myself?

Tranny:

slips in and out of first, when it shifts from 3rd to 4th, it kicks the engine RPM's down below 500, then back up. I've also lost some power above 3500 RPM. AW71 tranny. how involved is a switch to a stick shift? What could be wrong with the one I have now?

The brakes and front end also squeak, but there's plenty of pad and bushing, that's a project for the spring.

Oh dear, What's a boy to do?