I am kinda facing a similar dilemma on my E30.
Its a 4 door automatic eta and I havent really ever had it running right. I got it to be my daily driver, but I never seem to have the time to get it fixed. Whenever I do find the time for that car (mustang work or working on my moms 2 cars are higher priority) It dosent solve the problem. The most recent problem is that it started chugging and running like butt and ran better with the O2 disconnected and I just havent been motivated to mess with it (been months). I like the car, but hate its driveline.
I have put a new timing belt on it, readjusted the valves, plugs and wires, new vac hoses, transfer pump, etc. Still havent ever gotten it to run right.
I know I could fix it if I gave it some time and effort, but I am burning out on it.
Been really thinking about cutting it loose and just getting a FWD manual econobox to replace it, preferably something that wont steal wrenching time from my more fun cars.
Then again, I fell like if I could get it to run right I would be fine with its other faults and love it. 
current fix-it list on the car
Runs on wrong loop (efi) so runs like butt, odo went nonfunctional, slow windows (pass dosent work sometimes), leaky sunroof, funny sound sometimes turning right at a certian moderate degree (replaced wheelbearing early in ownership), leaky trunk, nonfunctional horn, drivetrain clunk (guibo and rear bushings?), etc..
formerly known as hotstang