hey all, have a 91 740, automatic, that just suddenly does not maintain rpm's at a stop sign or stop light. I have to hold the the brake down and keep my foot on the accelerator to keep it running while I wait for the light to change. Any idea how to solve this?
Thanks!

If this only happens when you put your foot on the brake then you may have a leak in the power brake vacuum booster diaphram. When the brakes are applied you loose vacuum and the engine will stall or run very rough. Does it happen if you let the car coast to a stop in neutral without applying the brake?

I agree with Duke, the throttle switch sounds like it isn't working. And if the throttle body is totally filthy, it can prevent the throttle from going far enough to make the stop. The gasket is just $1, and all it needs is a can of carb cleaner and some work to get it cleaned up. Definitely needed and worth the effort.
If you need more info on removing it to clean it, check the FAQ or reply here.
Good luck!
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Rob Bareiss, New London CT ::: '87 244DL/M47- 234K, '82 245T/M46-182K, '89 244DL/AW70- 212K Not too distant past: 86 244DL 215K, 87 244DL 239K, 88 744GLE 233K, 88 244GL 147K, 91 244 183K

No expert here, but I would definately clean the idle air valve and check the operation of the throttle switch on the throttle body. That is pretty easy to do with an ohm meter and the engine turned off. If the switch is not working the idle air valve won't operate-could just need adjustment. There's a lot of info in the FAQ about how to do that.

R Duke