5. Fuel System Delivery
5. Fuel System Delivery
WARNING: AVOID CONTACT WITH FUEL DURING A VISUAL INSPECTION FOR FUEL LEAKS WITH The ENGINE RUNNING. DO NOT WORK ON The FUEL SYSTEM UNTIL The PRESSURE "AS BEEN RELEASED AND The ENGINE "AS COOLED. FUEL IN The High- PRESSURE FUEL SYSTEM IS HOT AND UNDER VERY High PRESSURE. HIGH-PRESSURE FUEL MAY CAUSE CUTS AND CONTACT WITH HOT FUEL MAY CAUSE BURNS. FAILURE TO FOLLOW THESE INSTRUCTIONS MAY RESULT IN SERIOUS PERSONAL INJURY.
WARNING: WHEN HANDLING FUEL, ALWAYS OBSERVE FUEL HANDLING PRECAUTIONS AND BE PREPARED IN The EVENT OF FUEL SPILLAGE. SPILLED FUEL MAY BE IGNITED BY HOT VEHICLE COMPONENTS OR OTHER IGNITION SOURCES. FAILURE TO FOLLOW THESE INSTRUCTIONS MAY RESULT IN SERIOUS PERSONAL INJURY.
Note: The Diesel Fuel Flow Tester 310-193 or equivalent provides a pressure reading while simulating maximum fuel consumption at full load on the fuel system. The Diesel Fuel Flow Tester 310-193 uses a 1.193 mm (0.047 in) calibrated orifice integrated in the tool assembly to simulate the fuel consumption.
For E-Series vehicles, measure the fuel system pressure at the right hand cylinder head fuel passage plug on the back of the right hand cylinder head.
For F-Super Duty and Excursion vehicles, measure the fuel system pressure at the secondary fuel filter housing test poll.
The fuel pressure value at the secondary fuel filter housing test port is higher than the fuel pressure value at the back of the cylinder head due to a pressure drop through the fuel rails, fuel injectors and other fuel system components.
Note: Make sure the battery voltage is greater than 12.5 volts at all times throughout this procedure. Install a battery charger if necessary. Fuel pumps will not pass the fuel delivery tests if the battery voltage drops below 12.5 volts during the fuel flow tests. This is especially important if the test is carried out on a non-running vehicle because there are significant electrical loads when operating the fuel pump with the engine off 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 Charging System Symptom Chart to continue diagnosis.
Purpose:
The purpose of this test is to verify the fuel system pressure and flow.
Fuel System Delivery
Fuel System Delivery Recommended Procedure:
Note: Restrictions in the fuel line may cause continuous aeration.
^ 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.
^ Measure the voltage between the fuel pump power and ground circuits. Voltage is present for approximately 20 seconds after the key is turned to the ON position. If the voltage is less than 11.9 volts GO to Pinpoint Test M.
^ Make sure the valve on the Diesel Fuel Flow Tester 310-193 or equivalent is closed.
^ NOTICE: Correct installation of the Diesel Fuel Flow Tester 310-193 or equivalent is necessary to prevent damage to the interior of the vehicle.
For E-Series vehicles, remove the right hand cylinder head fuel passage plug from the back of the cylinder head. Install the Diesel Fuel Flow Tester 310-193 or equivalent using two new sealing washers 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 illustration 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.
For F-Super Duty vehicles, remove the test port plug from the front of the secondary fuel filter housing. Install the Diesel Fuel Flow Tester 310-193 or equivalent using two new sealing washers to seal the banjo bolt and torque to 27 Nm (20 lb-ft).
^ 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.
^ If the engine starts and does not stall, start the engine and let it idle.
^ Open the valve on the Diesel Fuel Flow Tester 310-193 or equivalent.
^ If the engine is running, run the engine until fuel flows free from cloudiness, gelling (cold weather) or aeration. If the fuel continues to be cloudy or gelled, refer to the Sufficient Clean Fuel test in this section. If the air bubbles can not be purged, check for kinks or leaks in the vehicle fuel system as well as the test tool.
^ If the engine does not start, continue to cycle the key to the ON position until fuel flows free from cloudiness, gelling (cold weather) or aeration. If the fuel continues to be cloudy or gelled, refer to the Sufficient Clean Fuel test in this section. If the air bubbles can not be purged, check for kinks or leaks in the vehicle fuel system as well as the test tool. The fuel pump cycles on, then off afier 20 seconds.
^ Access and monitor the B+ PID. Verify the battery and charging system are working correctly and the battery voltage is greater than 11.5 volts. Refer to Charging System for diagnosis as necessary.
^ 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.
Possible Causes:
^ Fuel return line restriction
^ Fuel pressure regulator valve
Tools Required:
Diesel Fuel Flow Tester 310-193 or equivalent
Fuel Conditioning Module Pressure
Purpose:
The purpose of this test is to verify that the fuel filters are not restricted.
Fuel Conditioning Module Pressure
Measure the fuel conditioning module outlet fuel system pressure between the fuel conditioning module and the secondary fuel filter.
Use the Diesel Fuel Flow Tester 310-193 or equivalent to simulate maximum fuel consumption.
Plug the vehicle's fuel return line to isolate the fuel pressure regulator valve.
Fuel Conditioning Module Pressure Test Recommended Procedure:
Note: Restrictions in the fuel line may cause continuous aeration.
^ Make sure the valve on the Diesel Fuel Flow Tester 310-193 or equivalent is closed.
^ Using the male and female tool plugs included with the Diesel Fuel Flow Tester 310-193 or equivalent plug the fuel return line between the secondary fuel filter and the fuel conditioning module. Plug the fuel conditioning module fuel return inlet port.
^ Install the Adapter Fuel Pressure Test 310-111 or equivalent with the Gauge 0- 100 KPa (0-160 psi) Bar (part of DSL ENG Pressure Test Kit 014-00761 or equivalent) between the fuel conditioning module outlet port and the fuel supply line leading to the secondary fuel filter.
^ If the engine starts and does not stall start the engine and let it idle.
^ Open the valve on the Diesel Fuel Flow Tester 310-193 or equivalent.
^ If the engine is running run the engine until fuel flows free from cloudiness gelling (cold weather) or aeration. If the fuel continues to be cloudy or gelled refer to the Sufficient Clean Fuel test in this section. If the air bubbles can not be purged check for kinks or leaks in the vehicle fuel system as well as the test tool.
^ If the engine does not start continue to cycle the key to the ON position until fuel flows free from cloudiness gelling (cold weather) or aeration. If the fuel continues to be cloudy or gelled refer to the Sufficient Clean Fuel test in this section. If the air bubbles can not be purged check for kinks or leaks in the vehicle fuel system as well as the test tool. The fuel pump cycles on then off afier 20 seconds.
^ Access and monitor the B+ PID. Verify the battery and charging system are working correctly and the battery voltage is greater than 11.5 volts. Refer to Charging System for diagnosis as necessary.
^ Record the maximum fuel pressure at the fuel conditioning module outlet while the valve on the Diesel Fuel Flow Tester 310-193 or equivalent is open and fuel is flowing back to the fuel tank.
If the fuel pressure at the fuel conditioning module outlet is below the 344 kPa (50 psi) MIN specification and new primary or secondary fuel filters have not been installed.
install new primary and secondary fuel filters. Repeat the Fuel Conditioning Module Pressure test in this section to verify the repair.
If the Fuel Conditioning Module Pressure test has been repeated and the fuel pressure at the fuel conditioning module outlet now meets the 344 kl)a (50 psi) MIN specification remove the fuel return line plugs and connect the fuel return line. Repeat the Fuel System Delivery test in this section to verify the repair.
If the Fuel Conditioning Module Pressure test has been repeated and the fuel pressure at the fuel conditioning module outlet is still below the 344 kl)a (50 psi) MIN specification carry out the Electric Fuel Pump Inlet Restriction test in this section.
If the fuel pressure at the fuel conditioning module outlet is equal to or greater than the 344 kPa (50 psi) MIN specification carry out the Restricted Secondary Fuel Filter test in this section.
Possible Causes:
^ Primary fuel filter
^ Secondary fuel filter
Tools Required:
Diesel Fuel Flow Tester 310-193 or equivalent
Adapter Fuel Pressure Test 310-111 or equivalent
Gauge 0-1~100 kPa (0-160 psi) Bar (part of DSL ENG Pressure Test Kit 014-00761 or equivalent)
Restricted Secondary Fuel Filter
Purpose:
The purpose of this test is to determine the condition of the secondary fuel filter.
Restricted Secondary Fuel Filter
Measure the fuel pressure difference between the fuel inlet and fuel outlet sides of the secondary fuel filter.
Restricted Secondary Fuel Filter Test Recommended Procedure:
Note: Restrictions in the fuel line may cause continuous aeration.
^ Make sure the valve on the Flow Tester Diesel Fuel 310-193 or equivalent is closed.
^ Using the male and female tool plugs included with the Flow Tester Diesel Fuel 310-193 or equivalent plug the fuel return line between the secondary fuel filter and the fuel conditioning module. Plug the fuel conditioning module fuel return inlet port.
^ Install the Fuel Pump Adapter 310-111 or equivalent with the Gauge 0-1100 kKPa(0-160 psi) Bar (part of DSL ENG Pressure Test Kit 014-00761 or equivalent) between the fuel conditioning module outlet port and the fuel supply line leading to the secondary fuel filter.
^ If the engine starts and does not stall start the engine and let it idle.
^ Open the valve on the Flow Tester Diesel Fuel 310-193 or equivalent.
^ If the engine is running 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.
^ If the engine does not start continue to cycle the key to the ON position until fuel flows free from cloudiness gelling (cold weather) or aeration. If the air bubbles can not be purged check for kinks or leaks. The fuel pump cycles on then off afier 20 seconds.
^ 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 Charging System Symptom Chart to continue diagnosis.
^ Record the indicated fuel pressure difference between the two installed test gauges while the valve is open and the fuel is flowing back to the fuel tank.
If the fuel pressure difference is greater than the specification install new primary and secondary fuel filters.
If the fuel pressure difference is less than the specification install a new fuel pressure regulator valve.
Remove the fuel return line plugs and connect the fuel return line to the fuel conditioning module repeat the Fuel System Delivery test in this section to verify the repair.
Possible Causes:
^ Secondary fuel filter
^ Fuel pressure regulator valve
Tools Required:
Diesel Fuel Flow Tester 310-193 or equivalent
Adapter Fuel Pressure Test 310-111 or equivalent
Gauge 0-1100 kPa (0-160 psi) Bar (part of DSL ENG Pressure Test Kit 014-00761 or equivalent)