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emcon5 emcon5 is offline
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Join Date: Nov 2000
Location: Reno
Posts: 6,486
That is the control box for the Lamda system.

On CIS-Lamda cars, fuel mixture is adjusted by controlling the duty cycle of the frequency valve. The Freq valve is essentially an EFI injector, on a fuel line going to the bottom chamber of the fuel distributor. It takes a rich/lean signal from the O2 sensor and adjusts the duty cycle up and down to compensate.

With no signal from the O2 sensor, the freq valve defaults to a slightly rich condition, but the freq valve is still operating. Without the control box (or the power relay next to it) it will not run, and you car will run really badly, if at all.

82 911SC Coupe
GTI Cup #43
Old 01-30-2004, 10:23 AM
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