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Fuel Analyzer Tech Tips

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In this article, we give you a few tips about the about the Fuel Analyzer including, the symptoms, fault Codes, Delphi Sealed Rail Kit, Delphi Diesel Centre and more.


  • Poor Starting
  • Increased Fuel Consumption

Look at Fault Codes

The technician connected Delphi’s DS150 diagnostic tool to the 16-pin EOBD diagnostics socket to interrogate the vehicle’s fault code history.

Fault returned ‘P0263 Injector cylinder 1 – Drift’ indicating an injector related fault.

Delphi Sealed Rail Kit

The technician checked all of the injector’s backleakage using the Delphi Sealed Rail Kit (YDT278) in order to identify which injectors are not performing to specification, and to confirm correct levels of rail pressure. In this case, it was a fault with one of the injectors, but if low rail pressure was an issue, the technician would have used Delphi’s False Actuator Kit (YDT410) to determine whether or not the pressure was generated mechanically by the pump, or if there was a possible fault with the pump’s Inlet Metering Valve (IMV) or Pressure Control Valve.

Delphi Fuel Analyzer

To ensure the damage was not due to contaminated fuel, the technician’s next step was to test the fuel within the system with Delphi’s fuel analyzer (YDT553). After testing the fuel from the vehicle’s tank, and/or the fuel filter assembly, it was found the fuel was not contaminated.

If the fuel analyzer had shown fuel contamination, the technician could use this diagnosis to explain the damage, as well as to refute any possible warranty claims. The fuel analyzer can be connected to a PC so results can be downloaded and printed for the workshop or customer's records.

Delphi Diesel Centre

Once the technician concluded the fault was a worn injector, he removed all of the injectors from the vehicle. As all of the injectors had done the same mileage, it was important to have the complete set diagnosed to rule out any other potential problems. The injectors were sent to a local Delphi Diesel Centre.

The Delphi Diesel Centre tested the injectors on a Delphi authorized test bench to confirm which injector was at fault. This included electrically testing the injectors for resistance and insulation failures.

New Calibration Code

After the injectors had been tested, any which did not pass the authorized test were dismantled, repaired and reassembled in a filtered clean environment. In this case the one repaired injector was, once again, put through a complete test procedure on an authorized test bench, and finally, recalibrated with a new C2i/C3i code, which was printed onto a label and attached to the injector body.

The new calibration code is critical for the operation of the repaired injector. When fitted to the engine, it allows the software within the ECU to accurately control the injector’s fuel delivery and switching times according to the specific parameters and performance for the vehicle.

Recalibrating the Vehicle

Once the technician received the tested, repaired and recalibrated injectors, he was able to re-fit them to the engine, continuing to maintain a high standard of cleanliness at all times. After the injectors were fitted to the engine, the technician utilized the DS diagnostic tool to calibrate the vehicle with the new C2i/C3i code for the repaired injector and to recheck the other three.

This is a straightforward process as the tool provides help files for the technician to guide them through the process.

Please note, recalibrating the vehicle with the new codes is essential – if the new codes are not entered, the vehicle will have poor running and idling issues, and fault codes are likely to be generated.

Clear Fault Codes

The final step for the technician was to re-interrogate with the DS diagnostic tool and clear all fault codes to confirm the fault was eliminated.

Job done!

Technician time: Approximately two hours…

Ensuring the repair is carried out correctly and efficiently the first time, on time!



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