I'm having troubles with a 16v wagon I just bought (199,000 km). She starts fine ,runs fine for a few moments (30 seconds) then starts to hunt, followed by rough idling. acceleration is bumpy too. She seems to run very rich. using the code reader at this point in time, shows no faults (1-1-1).
There was a crack (exh leak) in the cat conv. so I replaced it along with the o2 sensor. I also cleaned out the oil breather. The fuel pressure regulator looks very new too. I cleaned out the map sensor with spray cleaner and checked all the vacuum lines etc.. for condition/connection.
The problem is still just as bad.
The old o2 sensor was covered with sooty carbon along with the inside of the old cat conv and tailpipe.
I'd love to be able to adjust the mixture but there is no where to do that I think).

Any tips or info on this prob would be much appreciated.

Here's my story.
I have a 90 745 16v
it had an intermittent stalling problem and some errors... to make a long story short I cleaned every connection I could find under the hood, on the ecu and in the dash above it. I used this stuff called dielectric grease, it's about $8 for a can at autozone but well worth it. That solved a lot of the problems. I also changed the cap and rotor, and sealed them with ignition sealer and applied dielectric grease on all the plug wire connections, ran much better.
some wisdom I've learned is to make sure your idle switch is adjusted (where it clicks when you touch the throttle) and your thottle body is clean. Mine will probably always log a 2-3-2 error, about 1 a week. It says the mixture is too lean/rich at idle it's very vague.
Mine likes a bottle of injector cleaner every once in a while too.

here's a link to my other post, useful info
http://www.brickboard.com/RWD/index.htm?id=461790

good luck

Check/replace injector seals and intake manifold gasket, temp. sensor and make sure the injector ground wires are clean/tight. Other things are idle control, throttle body, clean and properly working.
Aaron

Had a little rough idle problem that progressed to hard-start stalling.

Turned out to be an old rpm sensor. It's just below the distributor on the bellhousing of the engine. Easy fix, definite wear item.

good luck, these cars run pretty nice if properly set-up.
jc
--
1985 740gle na, 1990 740gle 16 valve