My '93 E300 (3.2lt. dohc) has developed an un-steady idle at times. Follows not rime or reason. Sometimes it does it and sometimes it doesn't. Right now its less times then often but it appears to be occurring more often.
Idle will waver from low to high, up and down continuously till it stalls. If the air conditioner is on (and its nearly always on) it stalls easier (sooner). Its fine on the highway but in traffic its a nightmare.
My Mechanic says its most likely an Idle Control Unit. He says eventually it will stick to a higher position at around 1500 RPM's.
I am trying to find the part online. All I can find is a Idle Control Valve which cost about $160 USD. From what he was describing, it doesn't sound like the same thing.
Anyone think they know what it is? Part name?