All Other Models

NOTE: The CO meter is no longer used to adjust the idle mixture. Instead, mixture is adjusted using the VW 1367 dwell meter. The CO meter is used only to verify that oxygen sensor system operates properly.

Remove both connectors from idle stabilizer and connect them together. Run engine until oil temperature is above 176°F (80°C). Disconnect and plug PCV hose so fresh air can enter system. Turn off all electrical equipment.
On Rabbit and Scirocco models, remove charcoal canister vent hose at elbow below intake boot. On Quantum models, remove cap from "T" piece in charcoal canister vent hose near right fender well.
Connect CO meter to CO test point on engine using adapter hose (US 4492). Start engine and briefly accelerate. Check idle speed and adjust if necessary by turning idle speed screw on CIS throttle plate housing. Check ignition timing and adjust if necessary.
Remove plug from air sensor housing. Insert adjusting tool (P377) and adjust dwell with mixture adjusting screw. The dwell reading will fluctuate. Adjust so reading displays 38-52°. If dwell does not fluctuate check oxygen sensor system.

Check CO value. If value is too high, check for leaks in intake system and exhaust system. Also check fuel system for a malfunction. Reconnect tester and recheck idle speed. Adjust if necessary. Stop engine, reconnect PCV hoses, charcoal canister hose and idle stabilizer.

IDLE SPEED AND CO% LEVEL

Application

Idle RPM

CO%

Vanagon

Federal

Man. Trans.

800-950

0.5-1.5

Auto. Trans.

850-1000

0.5-1.5

Calif.

850-950

0.3-1.1

Rabbit w/Carb.

⁽¹⁾ 820-900

...

All Others

880-1000

0.3-1.2

⁽¹⁾	When adjusting only. When checking, 850-1000 RPM.