Abstract: A transducer device is provided which is arranged to be mounted on flow path-defining structure of a fuel injection system, preferably on the outside of a delivery valve housing including a chamber in which a surge of pressure is built up during operation of the injection pump to cause a transducer of the device to develop a high amplitude and high rate of change electrical signal. The device is readily clamped in place and is light in weight with a center of gravity close to the axis of the chamber, the effect of engine vibrations being minimized. The signal from the device and a signal developed at a predetermined rotational position of the engine crankshaft are applied to an instrument which indicates the relative timing of the signals and the RPM.

Abstract: Disclosed is a transducer assembly and diagnostic apparatus for processing an electrical signal which varies with the pressure changes occurring within an engine cylinder. The transducer assembly consists of a U-shaped structure integrally formed in a sandwich arrangement and encompassing a pressure-responsive crystalline element. The assembly is sized such that it substantially encompasses the shank of a spark or glow plug of the engine such that axial forces from within the cylinder excite the transducer through the plug to produce a signal which is processed in an electrical circuit to provide timing or other diagnostic information.

Abstract: A transducer and associated diagnostic system for fuel injected diesel engines of the type having glow plugs to provide supplementary ignition during starting and warm-up periods. A piezoelectric transducer unit is adapted to screw into the receptacle normally provided in each cylinder for a glow plug. The unit includes a piezoelectric element which is held under tension by a conductive rubber plug which coacts with a coaxial connector in transmitting the pressure indicative output signal. The transducer develops an electrical signal which varies in accordance with the pressure-time characteristic of the cylinder combustion chamber, the electrical signal representing performance of each cylinder being processed individually to provide timing and other valuable information or being combined with electrical signals developed for other cylinders of the engine in a comparative diagnostic system.

Abstract: Engine monitoring apparatus is disclosed in which the cylinder pressure changes in a fuel injected engine are monitored through the use of a transducer device which produces an electrical signal responsive to pressures exerted on an injector nozzle from within the cylinder. The transducer is mounted to the nozzle holding brackets or fasteners which act to maintain pressure tending to seat the nozzle against an inlet port in the cylinder and, as such, is responsive to axial pressures exerted on the nozzle assembly from within the cylinder. Methods and apparatus for mounting the transducer device to the holding brackets of various types of nozzle assemblies are disclosed along with read-out devices including a tachometer circuit for utilizing the transducer output signal for performance monitoring and diagnostic applications.

Abstract: Engine monitoring apparatus is disclosed in which the cylinder pressure changes in a fuel injected engine are monitored through the use of a transducer device which produces an electrical signal responsive to pressures exerted on an injector nozzle from within the cylinder. The transducer is mounted to the nozzle holding brackets or fasteners which act to maintain pressure tending to seat the nozzle against an inlet port in the cylinder and, as such, is responsive to axial pressures exerted on the nozzle assembly from within the cylinder. Methods and apparatus for mounting the transducer device to the holding brackets of various types of nozzle assemblies are disclosed along with read-out devices including a tachometer circuit for utilizing the transducer output signal for performance monitoring and diagnostic applications.