EGR Wide Open Throttle Valve: Testing and Inspection

Special Tools, Testers And Auxiliary Items:
- Fluke 83 multimeter (or equivalent)
- VW1594 connector test kit
- 12 mm hex drive and glow plug or equivalent spacer





Test Sequence:
- Disconnect 2-pin harness connector -1- from EGR part throttle switch -F166-.
- Measure resistance between EGR part throttle switch terminals using multimeter.
- Switch open (pump lever on idle speed stop): infinite ohms.
- Switch closed (pump lever toward WOT): 0 ohms.

Adjusting:

NOTE: The EGR part throttle switch, switch points are set by the manufacturer on a test stand and must not be altered.

Adjust new switches as follows:





- Operate injection pump lever and clamp 12 mm hex drive of glow plug between stop (arrow-1-) and lower edge of operating lever (arrow -2-).
- Press operating lever securely against glow plug (arrow -3-). In this position, adjust EGR part throttle switch by sliding unit in elongated holes until switch point (switch clicks) is just behind highest point on curved plate (arrow -4-).


NOTE: The upper EGR part throttle switch cover is shown removed to make the illustrated switch point more clear.