Connect scan tool with 'DATA LINK CONNECTOR'(DLC).
Warm engine up to normal operating temperature.
Turn all the electrical devices including air conditioner OFF.
Monitor "FUEL PRESSURE MEASURED", "RAIL PRESSURE REGULATOR" and "INJ. PUMP REGULATOR" parameter on the scan tool.
Idle (No load) | 3000RPM (No load) | ||
FUEL PRESSURE MEASURED | approx. 29 Mpa | Refer to the below graph. | Pressure increases |
RAIL PRESSURE REGULATOR(Rail) | approx. 19 % | Duty increases | |
RAIL PRESSURE REGULATOR(Rail) | approx. 19 % | Duty decreases |
☞ P-PRV installed on high pressure pump is controlled to reduce duty in order to increase rail pressure at acceleration. (P-PRV operating current decreases) → IF the current decreases, fuel amount to common rail from high pressure increases.
☞ Duty for PRV installed on common rail is increased in order to make rail pressure up at acceleration(PRV Operating current increases) → If the current increases, fuel feeded to common rail return amount is decreased that makes common rail pressure increases.
The waveform of fuel pressure regulator valve installed at high pressure pump(fuel detecting MPROP) shows approx. 30% duty at idle, duty decreases to approx. 25% at acceleration to raise rail pressure.The waveform of rail pressure regulator valve installed at common rail shows approx. 19% duty at idle, duty rises to approx. 45% at acceleration to raise rail pressure.