Fuel Injectors & Pumps – Section 8.4 Series 50/60 DDEC High Pressure Fuel Test

Section 8.4
Series 50/60 DDEC High Pressure Fuel Test

To determine if high fuel pressure is causing lack of power, perform the following steps:‪

1. Remove either the fuel pressure sensor or supply fuel temperature (SFT) sensor fitting from the secondary filter, if equipped. See current Series 60 service manual (6SE483) or Series 50 service manual (6SE50).
2. Install a tee fitting between the secondary filter and fuel outlet line.
3. Attach a calibrated gauge capable of reading 0-689 kPa (0 - 100 psi) to the tee fitting.
4. Start and run the engine to the speeds listed in Table "Engine Speed and Fuel Pressure" and record the fuel pressure.

   Engine Speed, rpm‪	Fuel Pressure, kPa (psi)‪
   600‪	103 - 152 (15 - 22)‪
   1200 - 1300‪	207 - 310 (30 - 45)‪
   1800 - 2100‪	448 - 552 (65 - 80)‪

   Table 1. Engine Speed and Fuel Pressure
5. Shut down the engine.
6. Remove the tee fitting and calibrated gauge from the secondary filter.
7. Reinstall any sensors that were removed.
8. Analyze the measured fuel pressure readings.
   1. If the fuel oil pressure is within specification, testing is complete.
   2. If the fuel oil pressure is outside specifications listed in table, check fuel pressure regulator.