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Home >> Porsche >> 1987 >> 911 Turbo, 2D Convertible >> Repair and Diagnosis >> Engine Performance >> System >> Fuel Injection System - BOSCH Cis >> Special Features >> Cold Enrichment System
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Cold Enrichment System

An electric switching valve is installed in vacuum line for retard control in order to also have proper emissions in the warm-up phase. This valve receives power from the acceleration enrichment control unit in the first minute after a cold start below 98°F (30°C) and stops vacuum. This advances the ignition timing, through which the idle speed is faster and emission control better.