B5.9G, B5.9LPG – Troubleshooting and Repair Manual – 005-009   Fuel Control Housing

WARNING  To reduce the possibility of severe personal injury or death when working on the fuel system, turn off the fuel supply at the vehicle’s main fuel shutoff valve before removing any component.

Before removing any component, turn off the fuel supply at the vehicle’s main fuel shutoff valve.

Start the engine and allow it to run at idle until it dies.

Disconnect the wiring harness connectors from the following components:

• Mixer inlet pressure sensor
• Wastegate control valve
• Fuel control valve
• Fuel shutoff valve (Natural Gas only)
• Humidity sensor (Gas Plus only)
• Fuel pressure/temperature sensor, secondary (Gas Plus only).

Disconnect the wiring harness connectors from the following components:

• Gas mass flow sensor
• Idle speed control valve (B5.9G and B5.9LPG only)
• Throttle position sensor (B5.9G and B5.9LPG only)
• Fuel pressure switch (B5.9LPG only).

WARNING  Fuel is flammable. Keep all cigarettes, flames, pilot lights, arcing equipment, and switches out of the work area and areas sharing ventilation to reduce the possibility of severe personal injury or death when working on the fuel system.

Remove the fuel supply line from the fuel control housing inlet.

Remove the charge air cooler hose from the inlet elbow.

Remove the fuel jumper hose from the fuel control housing and mixer.

Remove the two capscrews and fuel control valve.

Remove and discard the fuel control valve o-ring.

Remove the wastegate signal line from the intake elbow fitting.

Remove the three capscrews, inlet elbow, and o-ring seal.

Discard o-ring seal.

Hold the throttle body in place while removing the mixer.

Remove the four nuts and mixer from the throttle body.

Remove the four mounting nuts.

Remove the fuel control housing assembly.

Remove the following parts from the fuel control housing:

• Elbow (1)
• Two screws (2)
• Gas mass sensor connection adapter (3)
• Four screws (4)
• Gas mass flow sensor (5).

Discard all o-rings and replace with new.

Remove the following parts from the fuel control housing:

• Elbow (6)
• Four screws (7)
• Cover plate (8)
• Gasket (9)
• Pressure regulator valve (10)
• Coalescent filter (if present) (11).

Discard the old gasket (9) and replace with new.

Discard the coalescent filter (11). Do not replace, it is now obsolete.

Remove the following parts from the fuel control housing:

• Two screws (12)
• Fuel shutoff valve (13)
• Screen pack (14)
• Plug (15)
• O-ring (16)
• Rectangular seal (17).

Discard the o-ring (16) and rectangular seal (17) and replace with new.

The screen pack can be cleaned using non-residue electrical cleaner, Part Number 3824510. The screen pack must be replaced if the mesh is damaged.

Remove the following parts from the fuel control housing:

• Elbow (19)
• Two screws (20)
• Gas mass sensor connection adapter (21)
• Four screws (22)
• Gas mass flow sensor (23)
• Screen retainer (24)
• Screen pack (25)
• Fuel pressure switch (26).

Discard all o-rings and replace with new.

The screen pack can be cleaned using non-residue electrical cleaner, Part Number 3824510. The screen pack must be replaced if the mesh is damaged.

Remove the following parts from the fuel control housing:

• Fitting (1, 2)
• Two screws (5)
• Gas mass flow sensor connector adaptor (7)
• Four screws (4)
• Gas mass flow sensor (9)
• Two screws (5)
• Fuel shutoff valve (Natural Gas only) (10)
• Cover plate (LPG only) (not shown)
• Screen pack (8)
• Fitting (2).

WARNING  When using solvents, acids, or alkaline materials for cleaning, follow the manufacturer’s recommendations for use. Wear goggles and protective clothing to reduce the possibility of personal injury.

WARNING  Some solvents are flammable and toxic. Read the manufacturer’s instructions before using.

CAUTION  When cleaning the fuel control housing components, use Cummins safety solvent and degreaser, Part Number 3824510. Using other types of cleaners can cause damage to the plastic and electronic components in the fuel control housing.

Clean the following fuel control housing components:

• Low-pressure regulator (Natural Gas only)
• Fuel shutoff valve (Natural Gas only)
• Screen pack
• Fuel control housing
• Rear cover plate (Natural Gas only)
• Gas mass flow sensor connection adapter.

CAUTION  Do not remove the screen from the gas mass flow sensor. Permanent damage to assembly will occur.

Clean the gas mass flow sensor.

If the engine is experiencing a performance complaint due to oil contamination in the gas mass flow sensor, the sensor may have to be replaced.

Use cleaner, Part Number 3824510, to clean the screen pack.

Replace any part that can not be cleaned. Allow all parts to dry before installing.

Check all sealing surfaces for damage.

CAUTION  Any oil inside the gas mass flow sensor or on the screen pack will cause poor performance.

Apply a light coat of Lubriplate™, Part Number 3163086, on all o-rings before assembly.

Install the following parts on the fuel control housing:

• Rectangular seal (17)
• O-ring (16)
• Plug (15)
• Screen pack (14)
• Fuel shutoff valve (13)
• Two screws (12).

All o-rings and rectangular seals must be replaced.

Install the following parts on the fuel control housing:

• Pressure regulator valve (10)
• Gasket (9)
• Cover plate (8)
• Four screws (7)
• Elbow (6).

Do not replace the coalescent filter, it is now obsolete.

Install the following parts on the fuel control housing:

• Gas mass flow sensor (5)
• Four screws (4)
• Gas mass flow connection adapter (3)
• Two screws (2)
• Elbow (1).

CAUTION  Any oil inside the gas mass flow sensor or on the screen pack will cause poor performance.

Apply a light coat of Lubriplate™, Part Number 3163086, on all o-rings before assembly.

Install the following parts on the fuel control housing:

• Fuel pressure switch (26)
• Screen pack (25)
• Screen retainer (24)
• Gas mass flow sensor (23)
• Four screws (22)
• Gas mass sensor connection adapter (21)
• Two screws (20)
• Elbow (19).

All o-rings and rectangular seals must be replaced.

CAUTION  Any oil inside the gas mass flow sensor or on the screen pack will cause poor performance.

Apply a light coat of Lubriplate™, Part Number 3163086, on all o-rings before assembly.

Install the following parts on the fuel control housing:

• Screen pack (8)
• Fuel shutoff valve (Natural Gas only) (10)
• Cover plate (LPG only) (not shown)
• Two screws (5)
• Gas mass flow sensor (9)
• Four screws (4)
• Gas mass sensor connection adapter (7)
• Two screws (5)
• Fitting (1, 2).

All o-rings and rectangular seals must be replaced.

Install a new mounting sealing ring.

Apply a light coat of Lubriplate™, Part Number 3163086, on all o-rings before assembly.

Before installing the fuel control housing onto the studs, connect the fuel shutoff valve connector (Natural Gas only).

Slide the fuel control housing forward on the mounting studs until the flange and sealing ring fit flush with the housing.

Install the mounting nuts.

Lubricate the sealing ring with Lubriplate™, Part Number 3163086.

Install the mixer and four nuts.

Replace the fuel control valve o-rings with new o-rings.

Lubricate the fuel control valve o-ring with a small amount of Lubriplate™, Part Number 3163086.

Install the fuel control valve and two capscrews.

Replace the inlet elbow o-ring with a new o-ring.

Lubricate the o-ring with a small amount of Lubriplate™, Part Number 3163086.

Install the inlet elbow o-ring seal and three capscrews.

Install the wastegate signal line with a hose clamp to the inlet elbow fitting.

CAUTION  Be sure to use two wrenches when tightening the hose. Twisting and damage will occur to the fuel jumper hose if only one wrench is used.

Connect the fuel jumper hose to the mixer and fuel control housing.

Install the charge air cooler hose to the inlet elbow.

Connect the following wiring harness connectors:

• Mixer inlet pressure sensor
• Wastegate control valve
• Fuel control valve
• Humidity sensor (B Gas Plus and B LPG Plus only)
• Fuel pressure/temperature sensor, secondary (B Gas Plus and B LPG Plus only).

Connect the following wiring harness connectors:

• Gas mass flow sensor
• Idle speed control valve (B5.9G and B5.9LPG only)
• Throttle-position sensor (B5.9G and B5.9LPG only)
• Fuel pressure switch (B5.9LPG only).

Connect the fuel supply line to the fuel control housing inlet.

WARNING  Fuel is flammable. Keep all cigarettes, flames, pilot lights, arcing equipment, and switches out of the work area and areas sharing ventilation to reduce the possibility of severe personal injury or death when working on the fuel system.

Turn on the vehicle’s main fuel supply line.

Start the engine and let idle for one minute.

Shut off the engine.

Turn the key to the ON position only (do not
engage the starting motor) and check all connections for fuel leaks using gas detector, Part Number 3823984.

If leaks are found, close the valve, turn the key to the OFF position, and repair leaks.