1985 BMW 318i Will Not Idle Properly (HELP!)

I recently aquired a 1985 BMW 318i. It will not idle properly. When the engine is not in gear and moving, the engine will jump constantly between 900 and 1100 RPMs while idling. Everything else seems to be running properly. Someone told me that the idle control unit needs to be replaced. Do you think this correct? I have heard that there is an idle control valve; this is not the problem? I cannot locate the idle control unit. Someone told me that it is located in-between the glove box and dash, but I can't find it. Will someone provide me with detailed instructions or a diagram? I cannot afford a mechanic and am not savvy with cars. I cannot afford a manual, but wonder whether or not this information is provided in the Bentley manual.

I recently aquired a 1985 BMW 318i. It will not idle properly. When the engine is not in gear and moving, the engine will jump constantly between 900 and 1100 RPMs while idling. Everything else seems to be running properly. Someone told me that the idle control unit needs to be replaced. Do you think this correct? I have heard that there is an idle control valve; this is not the problem? I cannot locate the idle control unit. Someone told me that it is located in-between the glove box and dash, but I can't find it. Will someone provide me with detailed instructions or a diagram? I cannot afford a mechanic and am not savvy with cars. I cannot afford a manual, but wonder whether or not this information is provided in the Bentley manual.

I would look at the throttle position sensor and make sure the idle switch is working. Some people will stick their ear down next to the switch to hear for a "click" jaust as the throttle is moved off idle. Now that click means nothing if you dont verify proper operation with an OHM meter.

Also check for air leaks as your idle is too high. On another note- did someone try to adjust the idle by use of the throttle valve stop bolt? Its a no-no.

DieInterim

How do I check the throttle position sensor? I removed the cover between in-between the dash and glove box. I moved the hardware in and out of position several times while looking for the idle control unit. All of the sudden, the car started idling properly, steady at 600 or

700 RPMs. This is a coincidence? I still have a problem? What do you think it is?

I think perhaps this is not the car for you. If you cannot afford a mechanic and are not savvy with cars, this is most definitely not a car you want to have.

But I will suggest that it _could_ be the throttle position sensor, but that it probably isn't. It's much more likely to be the airflow sensor. But it could be all kinds of things, including the fuel injection computer. Do you know someone with a parts car that you can use to swap some stuff out? Start with the mass airflow sensor.

--scott