Fuel System Delivery Recommended Procedure: Notes
- Verify there is fuel in the tank.
- Verify the fuel temperature is above 0 °C or 32 °F to prevent testing with gelled fuel. Check for sufficient clean fuel, carry out the Sufficient Clean Fuel test in this section.
- Make sure the valve on the Flow Tester, Diesel Fuel 310-193 or equivalent is closed.
- NOTICE
: Correct installation of the Flow Tester, Diesel Fuel 310-193 or equivalent is necessary to prevent damage to the interior of the vehicle.
Remove the right hand cylinder head fuel passage plug from the back of the cylinder head. Install the Flow Tester, Diesel Fuel 310-193 or equivalent using two new copper gaskets to seal the banjo bolt and torque to 27 Nm (20 lb-ft). Make sure the banjo fitting is centered over the freeze plug as shown in the Fig 1 and the hose is routed under the right hand exhaust manifold next to the transmission to prevent sealing concerns due to cylinder head casting bosses.
- Insert the heavy duty black end of the clear yellow hose into the fuel tank filler pipe to drain the fuel into the fuel tank. Make sure the fuel return hose is not pinched or restricted. Do not substitute any other fuel return hose and do not change the hose length of 6.7 m (22 ft) clear yellow hose with 0.91 m (3 ft) heavy duty black hose end or the internal diameter (ID) of 6.35 mm (0.25 in). The heavy duty black end on the hose is used to reduce pinching between the fuel filler door and the vehicle body.
- Start the engine and let it idle.
- Open the valve on the Flow Tester, Diesel Fuel 310-193 or equivalent.
- Run the engine until fuel flows free from cloudiness, gelling (cold weather) or aeration. If the air bubbles can not be purged, check for kinks or leaks.
- Verify the battery voltage is greater than 12.5 volts. If the battery voltage drops below 12.5 volts, the battery may need to be charged or there may be a charging system concern, refer to the appropriate Charging System, Symptom Chart to continue diagnosis.
- Record the indicated fuel pressure while the valve is open and fuel is flowing back to the fuel tank.
If the fuel pressure meets the specification, no concern is present at this time.
If the fuel pressure is below the specification, carry out the Fuel Conditioning Module Pressure test in this section.
If the fuel pressure is above the specification, check the fuel return lines for a restriction. If no restriction is present, install a new fuel pressure regulator valve.