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JFairman JFairman is offline
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Join Date: Jul 2006
Location: S. Florida
Posts: 7,289
The stock lambda frequency valve on a stock unmodified aluminum USA lambda fuel head doesn't have any effect on control pressure like it appears your thinking.
It has no relation to control pressure at all.

The lambda frequency valve modulates lower chamber differential pressure in the fuel head to lower emissions and get better gas mileage when cruising and idleing. It does that by returning fuel to the return line going back to the gas tank.

This system along with a catalytic converter is what allowed Porsche to meet the EPA emission requirements to resume selling the 930 in the USA in 1986.

hope that helps.
Old 11-07-2010, 04:11 PM
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