The PCM is located on the top right side of the bulkhead. The PCM receives battery power from the PCM power relay through the chassis connector. Ground is provided through the chassis connector and also includes a case ground.
Each injector has a unique 10 digit code representing the flow characteristic of that injector. The IQA code is located on each injector head and is also printed on a factory label located on the engine. The factory installed label indicates the IQA data for all the original injectors installed at the factory. In addition,… Read More »
When the high pressure is relieved from the top of the nozzle needle, high pressure on the lower surfaces force the needle up and allows fuel to be sprayed into the combustion chamber. When the control valve is released, spring pressure and high pressure fuel moves the needle back up against the seat in the… Read More »
The lower hydraulic coupler piston moves the control valve down to relieve high pressure from the top of the nozzle needle (the control chamber). When the control valve is pushed fully down, it seals off an orifice in the intermediate plate, stopping that fuel flow path of high pressure fuel to the top of the… Read More »
The piezo stack is linked to the control valve of the fuel injector via a fuel-filled hydraulic coupler. The upper piston of the coupler is a larger diameter than the lower piston. This difference in diameter causes an increase in the linear movement of the lower piston (more travel). Note: If the hydraulic coupler is… Read More »
The piezo actuator is a stack of piezo crystals. When current is applied to the crystals, the crystals expand. When the PCM supplied current is removed from the piezo crystals, they contract. When the crystals contract, they create voltage (current flow reverses). PCM supplies current to the piezo stack and when the injector is de-energized… Read More »
There are eight fuel injectors; four mounted on each cylinder head. They are serviced without removing the valve covers. The Injector Quantity Adjustment (IQA) must be programmed into the PCM when a new injector is installed. The injector is a 19 mm piezo-actuated injector with an 8 hole nozzle. Each fuel injector is retained with… Read More »
The high pressure fuel lines run between the: • high pressure fuel pump and left fuel rail. • right and left fuel rails. • fuel rails and the fuel injectors on the outside of the valve covers.
The fuel rails on the 6.7L Power Stroke® diesel engine are on the outside of the valve covers. The left fuel rail has the FRP sensor and the PCV solenoid. The right fuel rail does not have any sensors or solenoids. The left fuel rail is longer due to a diverter volume.
The FRP is threaded into the front of the left fuel rail. The FRP sensor is a three-wire variable capacitance sensor. The PCM supplies a 5 volt reference signal which the FRP sensor uses to produce a linear analog voltage that indicates pressure. The FRP sensor actively monitors fuel rail pressure to provide a feedback… Read More »