6.
Monitor 'Rail Pressure Regulator (pump)' at 50~70 ℃ fuel temperature and Idle rpm.
Sudden poor power and poor acceleration above certain rpm while driving could be caused by abnormal fuel system, intake and exhaust system leakage, abnormal EGR system, abnormal VGT system, abnormal CPF system. The purpose of this inspection is to analyze the cause of poor power and poor acceleration.
IG KEY "ON", ENGINE "ON".
Connect GDS(scantool) to Data Link Connector (DLC).
Allow the engine to warm up to normal operating temperature.
Electrical system and A/CON "OFF".
Select 'Fuel Pressure', 'Fuel Pressure -Target', 'Engine speed ', 'Fuel Quantity', 'Rail Pressure Regulator(Pump)' parameters on the GDS(scantool).
Monitor 'Rail Pressure Regulator (pump)' at 50~70 ℃ fuel temperature and Idle rpm.
Monitor that 'Fuel Pressure -Target' and 'Fuel Pressure' data should be almost same.
Monitor that 'Fuel Pressure' data should be stable.
Use graph function after selecting 'Fuel Pressure', 'Fuel Pressure -Target' and 'Engine speed' parameters on the GDS(scantool).
Monitor that 'Fuel Pressure -Target' and 'Fuel Pressure' data should be almost same at stall test (acceleration).
Refer to "Stall test" of detail inspections (Equipment settings).
[ Rail pressure data at normal acceleration (load is applied) ]
[ Rail pressure data at normal acceleration (load is not applied) ]
☞ There is a different between target fuel pressure and fuel pressure after acceleration → deceleration (when load is not applied), but it is normal control state.
Symptom | Inspection procedure | |
Case1 | ● Fuel system data are normal and 'Fuel Pressure' is controlled well by ECM to follow 'Fuel Pressure -Target'. | ● Go to "EGR & MAFS inspection" |
Case2 | ● 'Fuel Pressure' is unstable or 'Rail Pressure Regulator (Pump)' data is abnormal. ● 'Fuel Pressure' is NOT controlled by ECM to follow 'Fuel Pressure -Target' at stall test, finally poor acceleration occurs or engine stall | ● Go to "Low fuel pressure inspection" |
