Acceleration Enrichment Module: Description and Operation

Begining with November '84 production (engine KH), the 5000 turbo is equipped with a pressure gradient switch for cold acceleration enrichment.

When the engine coolant temperature falls below 65°C (149°F), vacuum is applied to the pressure gradient switch through the thermo vacuum switch on the left rear of the cylinder head.

During acceleration, until the engine is warmed up, the presure gradient switch will close for approx. 0.4 seconds. This will temporarily ground the oxygen sensor frequency valve and provide a 100% duty cycle for acceleration enrichment.