Abstract: A method of making a capacitive pressure sensor preferably for a vehicle fuel system with a flexible diaphragm, spacer and rigid substrate disposed in opposed face-to-face relation in a housing and yieldably urged together by a spring clamp. Electrodes disposed on the immediately adjacent opposed faces of the diaphragm and substrate produce a signal indicative of and varying with changes in the pressure of fluid acting on the diaphragm to displace its central portion relative to the substrate. In operation, through sensor and control circuitry, the speed of a fuel pump is varied to vary and control the pressure of fuel supplied to an engine in response to varying engine operating loads and conditions. To control the flow of fuel, a check valve, pressure relief valve and vent valve may be provided in the housing.

Abstract: A fuel pump manifold for a no-return fuel system for an automotive engine. The manifold has inlet and outlet passages with a check valve which opens when fuel is supplied to the engine and closes to prevent reverse flow of fuel when the outlet pressure is greater than the inlet pressure and a vent valve between the outlet and inlet and in parallel with the check valve which is normally closed and opens when the outlet pressure exceeds the inlet pressure by at least a predetermined minimum value which is usually the desired minimum pressure of fuel supplied to the operating engine when idling. Preferably, a normally closed pressure relief valve also communicates with the outlet to relieve overpressure of the outlet fuel supplied to the engine.

Abstract: A capacitive pressure sensor preferably for a vehicle fuel system with a flexible diaphragm, spacer and rigid substrate disposed in opposed face-to-face relation in a housing and yieldably urged together by a spring clamp. Electrodes disposed on the immediately adjacent opposed faces of the diaphragm and substrate produce a signal indicative of and varying with changes in the pressure of fluid acting on the diaphragm to displace its central portion relative to the substrate. In operation, through sensor and control circuitry, the speed of a fuel pump is varied to vary and control the pressure of fuel supplied to an engine in response to varying engine operating loads and conditions. To control the flow of fuel, a check valve, pressure relief valve and vent valve may be provided in the housing.