To determine if high fuel pressure is causing lack of power, perform the following steps:
Remove either the fuel pressure sensor (FPS) or fuel temperature sensor (FTS) fitting from the secondary filter, if equipped; see Figure
20414
for FPS and see Figure
20415
for FTS.
Engine Fuel Pressure Sensor
Engine Fuel Temperature Sensor
Install a tee fitting between the secondary filter and fuel outlet line.
Attach a calibrated gauge capable of reading 0 - 100 lbin.2
to the tee fitting.
Start and run the engine to the speeds listed in Table
and record the fuel pressure:
Note:
When checking fuel pressure, start the engine, run at the speeds listed in Table
, and record fuel pressure. Shut down the engine.
Engine Speed, r/min
Fuel Pressure, psi (kPa)
600
15 - 22 psi (103-152)
1200 - 1300
30 - 45 psi (207-310)
1800 - 2100
65 - 80 psi (448 - 552)
Fuel Pressure at Various Speeds
Shut down the engine.
Remove the tee fitting and calibrated gauge from the secondary filter.
Install a new check valve; refer to OEM guidelines
Verify check valve and restricted fitting replacement; refer to section
.
NOTICE:
Do not increase the size of the orifice in restricted fittings. Increasing restricted fittling hole size can cause injector caviation, resulting in reduced durability of injectors and other engine components, and increased engine emissions.
Test the Engine with Replaced Check Valve and Restricted Fitting
Perform the following steps to determine if the replaced check valve and restricted fitting resolved lack of power condition:
Refer to section
for exhaust caution before preceeding. Start and run the engine.
Run the engine at idle with a no-load for approximately 5 minutes, allowing the engine coolant to reach normal operating range.
Test drive the vehicle to ensure lack of power has been resolved.
If no lack of power occurred during the test drive, no further troubleshooting is required. Shut down the engine.
If lack of power occurred during the test drive, shut down the engine. Check for high fuel oil temperature return; refer to section
.