Diagnosing Toyota Hilux CRD Fault with Foxwell CRD700 & NT644
We arrived a Park Automotives on the day prior to filming, after a discussion with Gary, he pointed out that he was not able to make aconfident diagnostic decision without measuring the rail pressure. So we arrived the following day with the CRD700 Common Rail Diesel Pressure Tester to provide some assistance to Gary with his diagnosis, in return for letting us film the “Case Study”.
Make : Toyota
Model : Hilux
Year : 2006
Gearbox : Manual
Engine : 1KD-FTV
Series : KUN26R
Drive : 4X4
Body : Cab Chassis
Milage : 244,000 k’s
THE HISTORY
Symptom : No start situation, engine cranking
Repair History : This vehicle has a checkered past, less than 5,000 k’s ago, the vehicle was filled with on site drum fuel and subsequently had drivability issues, the on site technician had emptied and cleaned the fuel tank, replaced the fuel filter, replaced the suction control valve and replaced and programmed the injectors.
4-5 months and 5,000k’s later the vehicle broke down and would not restart, the on site technician had exhausted his diagnostic abilities and the vehicle was towed to Gary’s workshop.
When Foxwell arrived at Gary’s (one of local customers / friends) he mentioned that he was unable to rule in / out faults without measuring the rail pressure. So we stepped in with the CRD700 and the NT644, apowerful CRD Diagnostic Tool Combination.
Possible Causes
-High Pressure Line Leak
-High Pressure Pump
-Common Rail
-Pressure Discharge Valve
-Rail Pressure Sensor
-EDU
-ECU
-Injectors
The first test we did with the Foxwell CRD700 was to measure the CRD Rail Pressure to confirm the accuracy of the Rail Pressure Sensor, this was done to rule out the sensor, its wiring and the ECU’s interpretation of that data. IE, is the information being displayed in the live data accurate.
The Foxwell CRD700 high pressure tester was installed on the vehicle with a using the fitting kit T piece, the M12 / M12 flexible high pressure hose and one the vehicles existing fuel pressure lines.
Using the Data Graphing Function of the NT644 Automaster Pro, we compared the graphed Rail Pressure 10,000 kpa / 100 bar with the measurement taking using the CRD700.
A CRD VEHICLE NEEDS ON AVERAGE 350 BAR / 35,000 KPA TO START.DENSO HP3 PUMPS IN 1KD-FTV ENGINES HAVE TO REACH A MINIMUM OF 15,000KPA BEFORE THE ECU WILL SEND ANY INJT SIGNALS TO THE EDU TO DRIVE THE THE INJECTORS.
SENSOR RAIL PRESSURE IN LIVE DATA – 100 BAR
MEASURED RAIL PRESSURE – 99 BAR
With the two measurements confirmed and the vehicles rail pressure deemed to be accurate, we needed to know why the rail pressure was low. With Gary having eliminated the pre delivery side from the equation, and with no leaks between the pump and injectors we needed to rule in / out the injector pump itself. We did this by doing a maximum pressure test, where the CRD700 pressure sensor is fitted directly to the high pressure out put of the injector pump.
THE CRD700 HAS AN AWESOME FEATURE FOR PERFORMING THIS TEST. THE STARTER MOTOR SOLENOID (OR RELAY) IS CONNECTED TO THE TOOL SO YOU CAN SAFE TEST THE MAX OUT PUT PRESSURE OF THE INJECTOR PUMP, WITH THE IGNITION SWITCH ON, SELECT MAX PRESSURE TEST FROM THE CRD700’S MENU, THIS WILL ENERGISE THE STARTER MOTOR SOLENOID FOR 4 SECONDS. THIS ENSURES A SAFE ISOLATED TEST OF THE INJECTOR PUMP.
THE DIAGNOSIS
The isolated max injector pump pressure test was completed and found that on a 4 second crank, the injector pump is producing 1,500 Bar / 15,000 kpa, more than enough for Gary to confidently rule out an injector pump issue.
After removing and testing the injectors gary found Injectors 2 and 3 where leaking -into return-. After replacing and programming the injectors Gary retested the vehicle and found the pressures where all within specification.
A great tool, I ended up buying it that day, there is no other way I could have diagnosed that fault that quickly and with that accuracy. 10 out of 10 tool.
Foxwell NT644
Foxwell CRD700
