idle problems

[maxwell5ke]

84'bmw 728i idles off- from cold start it works well until engine heats up then it stalls during idling-i have checked the cooling system-works-it is not the fuel air mixture-checked that-i hav no ideas-please help

[lincolnmaster80]

I'm not sure if the 84's have this, but have you checked the DK's (Drosselklappe's = Throttlebodies) Sometimes these get gummed up and are never cleaned out and can run rough or stall.

[maxwell5ke]

what are throttlebodies? how do i check them?-when the engine is cold the car idles fine-when it heats up then it stalls-i found that the thermostat-cooling-is dead so al replace-but that wouldnt be the cause?i have checked all other essentials-distributor, spark plugs, rings, fuel pump and filter,ingectors,no blocks in any pipes-what else?

[lincolnmaster80]

Throttlebodies are the housing containing a valve to regulate the airflow through the intake manifold. The throttlebody is usually located between the air cleaner and the intake plenum. If it's possible, take off any of the tubing and you'll see a circular plate that hinges in the middle and it'll flap open to allow air in.

It's possible that the thermostat is causing the problem. It MIGHT be possible that there's a sensor that senses when the thermostat isn't working any more and shuts off to protect your engine. This is just one possibility, I'm not too familiar with the E23 7er's and I don't know if there is a thermostat sensor aside from the thermostat sensor itself. These cars were very advanced for their time and a lot of the technologies that they had didn't even hit the North American market until 3-6 years later on average.

Also, do you have cat's on your exhaust? I'm not sure if they came with them. If you do, have you checked the Lambda (O2) sensor?

[lincolnmaster80]

I can't remember if this is with the swords on the E32's or if you can also do this with the throttlebody, but here goes. Basically, disconnect the electrical connector to the throttlebody. Apply 12V of power to the throttlebody power and earth leads and it should come open fairly fast if it doesn't need to be cleaned. If it seems to open slowly or stick in certain spots, open it up and clean with intake/carb cleaner.

In doing some investigating into your rough idle, your ICV (Idle Control Valve) might also be shot. Apparently, this is under the air intake tubing right before the throttlebody. I'd check this first.

Like I said I'm not too familiar with the E23 7er's so my help to you is very limited, but I will do all that I can for you!

[lincolnmaster80]

Had another idea for you. I have found this group of people also very helpful.
http://www.the7seriesregister.co.uk/forums/
They are a UK based register, but they're a crazy bunch...I mean great bunch of people willing to help fellow 7er-holics out and keep our beloved machines running.

I have posted your problem on there to see if they can suggest anything. You can follow the post here:
http://www.the7seriesregister.co.uk/...=0&#entry44846

I think you HAVE to register to see the post and replies. If you wish to not register there, some of them might register here and reply, or I can post their replies on here for you to read and get your problem fixed! Sorry for the spam posting...