From a point at sea, to the circles of your mind, this is PM:
I have an 83 240GLE with the B23E motor. We have had some rain so i sprayed
all leads with WD40. The beast starts fine and idles ok. However, when it
is wared up it idles around 12-1300rpm. Any clues?
Auxiliary AIr Valve. It sits on top of the valve cover, and has a
couple of rubber hoses and an electrical connection to it. Its purpose
is to let more air past the throttle valve when the engine is cold,
but closes as the engine warms up.
You'll find a description of how it works here:
http://www.auto-solve.com/mech_inj.htm#MFI12
The easiest way to test if this is the culprit is to warm the engine
up and then pinch one of the air hoses to restrict the air flow. If
this brings the idle down, then the valve is either faulty, or not
getting any current.
--
Stewart Hargrave
A lot faster than public transport
For email, replace 'SpamOnlyToHere' with my name