I believe what johanb means is, while the engine is running and "humming"
unplug the IAC (idle air control) valve - you'll probably have to keep the
throttle open slightly to keep the engine running, which you will want to
do, since I assume the humming doesn't occur when the engine isn't running.
If the humming noise stops (when the IAC is unplugged and the engine is
running) it's likely the problem is the IAC valve itself. The humming noise
is a common symptom of IAC failure (another being the engine won't start or
idle without pressing the accelerator, especially when the weather is cold).
It was an easy fix on my '96, I think the '95 are pretty similar. When mine
started doing this it was usually only at idle - the noise wasn't noticeable
while driving. Sounded kind of like a small horn in the engine compartment,
many describe it as a moose call. There's a good thread about it (with
pics) at the "Serious Explorations" message board
"johanb" <ollieb1oREMOVE@THIScs.com> wrote in message
> try disconnecting iac sensor, it will stall but see if the humming noise