Abstract: A method and apparatus for measuring and controlling the temperature of fuel inside a fuel injector is provided. A first resistive element having a resistance that varies with temperature is positioned proximal the fuel within a fuel injector and a second resistive element having a known resistance is placed in series with the first resistive element and connected at a node. When a known voltage is applied across the resistor-divider network, the voltage generated at the node corresponds to the temperature of the fuel within the fuel injector. The first resistive element may also be used to heat the fuel within the injector to a predetermined temperature. Logic circuitry prevents energizing the first resistive heating element if any fuel injector coils are energized, thereby ensuring full voltage is available to drive the fuel injector coils.

Abstract: A method and apparatus for measuring and controlling the temperature of fuel inside a fuel injector is provided. A first resistive element having a resistance that varies with temperature is positioned proximal the fuel within a fuel injector and a second resistive element having a known resistance is placed in series with the first resistive element and connected at a node. When a known voltage is applied across the resistor-divider network, the voltage generated at the node corresponds to the temperature of the fuel within the fuel injector. The first resistive element may also be used to heat the fuel within the injector to a predetermined temperature. Logic circuitry prevents energizing the first resistive heating element if any fuel injector coils are energized, thereby ensuring full voltage is available to drive the fuel injector coils.

Abstract: A method and apparatus for controlling a heated tip injector having a connector with more than two pins. In one embodiment, the method includes (a) providing a plurality of heated tip injectors each having a coil and an internal heater; (b) maintaining all the internal heaters in an OFF state while the engine is cranking; (c) maintaining an internal beater in an OFF state if any of the coils are ON; and (d) maintaining an internal heater in an ON state if the engine is not cranking and all the internal heater coils are OFF.

Abstract: An internal heater for a fuel injector includes an array of plates of a positive temperature coefficient (PTC) material arranged about the valve element in a square tube shape, and surrounded by a heat insulating polytetrafluorethylene sleeve. The plates are preferably coated with polyimide to be protected from the fuel which flows over both surfaces of the plates. Electrical connections are established by inner and outer bands attached to the plates, with a conductive disc having tabs extending to the bands. Spring-loaded contact pins located radially outward from a seal on the disc have wires extending to the connector body contacts of the injector.