There are two reason for high idles...
1. Bad idle module... this is verified by doing a MB specified diagnostic
procedure and measurement... Simple test is to unplug the air valve wire
(not module unit)... if unplugging raises the RPM even higher then see #2.
2. Massive vacuum leak.... most likely is the black vacuum tube... rigid
one... on passenger side of the engine. Otherwise, spray carb cleaner to see
where engine idle would change (stumbles a bit)
Well I unplugged the 2 wires going to the idle valve, and nothing
happened. So I ran 2 wires from the battery to the valve, and the
engine dies when I attach the jumper wires, so I think the idle valve
is working fine.
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