Cold Enrichment Breaker (CEB) System

Fig. 97 No. 1 Cold Enrichment Breaker System:

Fig. 98 No. 1 Cold Enrichment Breaker System Schematic:

The No. 1 cold enrichment breaker system uses a vacuum control valve (VCV) to lean or richen the air/fuel mixture in response to engine warm-up conditions. The vacuum control valve responds to manifold vacuum, to reduce CO and HC emissions. When intake manifold vacuum exceeds 11.61 in.Hg (M/T) or 7.68 in.Hg (A/T), the VCV opens allowing air to be drawn in through the main air bleed and leans the mixture.

Fig. 102 No. 2 Cold Enrichment Breaker System:

Fig. 103 No. 2 Cold Enrichment Breaker System Schematic:

The No. 2 cold enrichment breaker system uses ECU control to lean or richen the air/fuel mixture in response to engine temperature and operating conditions. The ECU uses inputs from a vacuum switch and a bimetal vacuum switching valve (BVSV), to operate a vacuum switching valve (VSV).

Fig. 104 No. 2 CEB System Operation Chart:

When the engine reaches normal operating temperature, the input signals received from the vacuum switch tell the computer (ECU) to open or close the VSV. The vacuum switch responds to changes in engine load. The air/fuel ratio is adjusted by opening or closing the air passage to the main air bleed.