740il Rough Idle - solved

[gwoods922]

I recently purchased this vehicle and sadly it has been very poorly maintained. That being said, i have started the long road to recovery with o2 sensors, plugs, valve cover gaskets (oil pooling in plug tubes) and battery. I just ordered 2 throttle cables should be here tommorow. The reason i ordered 2 is that a google search revealed the "choke cable" is the same as the throttle cable and subsequent searches provided no different part numbers. In all honesty it was like pulling teeth to find the accelerator cable alone. I digress, both cables are trashed and replacement seemed like a good idea regardless. After the above work (aside from the cables) the engine ran/sounded much better. If i hold the pedal to about 900rpm in park or neutral the engine smooths out nicely. However yesterday on my way to work the vehicle died at a stop in drive twice. Which is a new symptom. Previously it seemed like it wanted to die but wouldnt regardless of how long i let it idle. I have only been driving it for a few days to figure out the quirks that need addressed before making it my daily moneypit i mean driver.
Full symptoms include rough idle in any gear, slow throttle response, intermittent hard shifting, "check control" on dash, "code" on radio, "rich" smelling exhaust, and , check engine light- original codes are vent valve, o2 bank 1 and 2, o2 control, and can bus failure. When i did plugs and gasket on pass. Side, one of the o2 codes did not return. I will scan it again once i get to work tommorow to verify that no other codes are present, gather as much live data as i can and do a reset to see what comes back on after another blast or 2.
Any diagnostic help would be appreciated. Even so much as a push in the right direction. Im just not trying to throw parts at something unless it is without question a problem. Thanks in advance guys/gals.

[G46]

did u manage to check the vacuum lines?

i previously got a very rough idle on my 730i, due to cracked vacuum line, i replaced them all at once, using the universal silicone vacuum line. also you need to check is the MAF. ICV,

and i recently know that TPS contributes to the idle, upon the throttle plate closes, it will make a contact internally on the tps, sending signal to the ICV to activate. or else, if it breaks the contact inside, it will only rely on the very small throttle butterfly plate opening, which in result will makes the ecu spinning its head, by adding more fuel (in old folk term, choke enrichment) due to less air coming in, and keeping it alive.

[gwoods922]

I haven't thoroughly checked all of them.
When i changed the air filter i didnt notice anything obvious im that area. But i will certainly add that to the checklist for tommorow evening as well as pulling the maf and update my findings. Are there any in vac lines in particular i should look for? I had planned on replacing them as it became necessary but upon reading a few other threads, as well as your comment, i have come to the realization that the vaccuum lines on these vehicles are far more important than i previously thought and replacing all of them at once is a worthwhile venture. I planned on swapping the tps when i did the throttle cables as well.
Is there a way to test the icv?
And Thank you for your input G46!

[shogun]

These links will help
https://www.bmwtechinfo.com/repair/main/
http://www.realoem.com/bmw/select.do
http://shark.armchair.mb.ca/~dave/BMW/e32/

[Timm]

These will help too:

http://www.meeknet.co.uk/e31/BMW_M60...cuum_Leaks.htm

http://www.meeknet.co.uk/E38/Diagnostics.htm

[G46]

those 2 masters, Shogun and Timm would be happy to assist you in a lot of situation. and dont forget to check the air intake boots, post MAF, those boots are jerks.

[gwoods922]

You guys are great thanks for all the help. I still havent gotten into the garage yet to look her over. Got a lot of personal stuff going on right now. My wife is expecting in july.. i will update as soon as i get some diag time in. Thanks again shogun and timm! Ive started looking over some of those links and there is alot of good info there

[gwoods922]

Okay finally got some time in on this P.O.S.
Throttle body gasket was sucking a ton of unmetered air...
Swapped that, cleaned the IACV, did the motor mounts, (which were completely separated) Cleaned it all up good and shes purring like a kitten. A leaky kitten bit a kitten none the less. I noticed the main drive belt can be removed by hand, so a tensioner is in my near future as well as possibly a new alternator... never saw an air cooled one before and it was full of road debris. Blew it out and replaced the hose running to it because it was wrecked. Cant thank you guys enough for pointing me in the right direction