Idle Stabilizer location

[msumbry@spacecom.af.mil (HQ AFSPC/IG)]

I'm restoring a 1979 Audi 5000S. My question concerns locating a device called the 'Idle Stabilizer.' I purchased a repair manual published by Haynes to help clear up some of the technical questions I had about the 
operations of various systems. One problem is the engine starts with difficulty, and I have to play games with the accelerator to keep the engine running until it warms up. One test recommended in the Haynes manual
is to bypass the Idle Stabilizer (Haynes manual #428, page 296, figure 13.13). I've searched the engine compartment completely and don't see any modules or devices closely approximating the picture in figure 13.13.
This car has the 2.2 litre engine, fuel injection, with air conditioning, and manual transmission.

Where is the Idle stabilizer? Alternatively, did all the fuel injected 5000Ss have this device installed?

The fact that playing with the accelerator keeps the engine running until its warm MAY NOT be symptomatic of an Idle stabilizer problem. So, what else might I investigate to resolve my problem?
MRS sends