Steve, the most common component that burns out on the ISCU is a power
transistor. I have replaced my with an audio transistor (NPN I think but you
had better check to be sure). IMHO this transistor burns out when the Idle
Stabilizer Control Valve starts making demands for too much current. I think
this happens when the valve starts to stick. I can't prove any of this but
its fun to speculate. Anyway it can't hurt to clean/lubricate the ISC valve
as well as replace the transistor.
If its not the transistor, I can't help you, sorry.
-Larry
-'86 Syncro Westfalia

"William S. Brown Jr." wrote:

> Does anyone know where I can get a schematic for inside of the Idle
> Stabilizer Control Unit?  I have an 86 Vanagon with the 2.1 L engine.  I
> have opened mine and found a burned part.  I don't know what it is, so a
> schematic would sure help.  Cheep to fix, if I can find out what the part
> is, but expensive to buy a full replacement.
>
> Steve
> brown6@alaska.net
> 86 Vanagon