usually that sort of hum is from the actuator either being blocked or going bad, they vibrate and thats what the noise is.
when does it do it, if it does it all the time, check to see if the butterfly is vibrating.
i talked to someone just now that says that its normal for it to buzz when the key is in the on position.
can anyone go out to their car and just confirm if it does or doesnt make any buzzing noises with the key in the on position, (you'd probably have to have the engine lid open to hear it, maybe put your hand on it and see if you feel anything).
Wait a second. Is a physical buzz or an electrical sounding buzz?
If it's an electrical sounding buzz then it's completely normal. I thought you meant like a physical buzz that comes from excessive vibration.
I hear it right before I turn the ignition on, and I move on from just powering the radio and clock to powering all the windows and DBW. I think the DBW sucks up a decent amount of electricity when the car isn't on (engine running).
What i really need to know is if the butterfly valve is moving on a good throttle body. See the problem is when i rev up to any RPM (car revs no problems), let off the gas, the car goes down in RPM and turns off. If anyone has any ideas let me know. Charlie picked the problem out right away and I trust he is correct. I just want to verify before blowing some cash.
solenoids will vibrate, thats normal and depending on the manufacturing tolerances on it, some will do it more than others, it'll sound more like a strong hum than a buzz though. I used to work in arcades and when the solenoids of the bandits would start to go the hum got louder and louder til it became a buzz.
that vibration is amplified through the mechanical parts and again depending on tolerances will cause the plate to oscillate, typically i've found that as they degrade the vibration gets worse when they are engaged, sometimes depending on the design if the solenoid can't get back to the a rest position it'll vibrate too as the system is fighting back and forth trying to open or close, this usually causes excessive heat and damages the windings, its probably a motor in the dbw but the principle is similar, if its a servo, then its called servo buzz again its normal and tolerances vary but you want it to be as little as possible.