B5.9G, B5.9LPG – Troubleshooting and Repair Manual – 005-094   Fuel Evaporator

NOTE: On B LPG Plus, Fault Code 2119 (Low Fuel Pressure, Primary), Fault Code 482 (Low Fuel Pressure, Secondary), and Fault Code 2219 (Oxygen Sensor in Range Failure) may log.

Start the engine and allow it to run at idle.

Turn off the vehicle main gas supply line.

Allow the engine to run until it dies.

Drain the cooling system. Refer to Procedure 008-018.

Disconnect the fuel shutoff valve.

Disconnect the following connections:

• Fuel supply line from the magnetic in-line filter at the inlet port
• Fuel supply line at the fuel filter housing
• Relief valve line
• Coolant supply and return lines.

Remove the mounting capscrews from the evaporator mounting brackets.

Remove the evaporator assembly.

Disconnect the following electrical connections:

• Fuel shutoff valve
• Primary fuel pressure sensor.

Disconnect the following connections:

• Fuel supply hose
• Fuel supply hose at the fuel filter housing
• Fuel pressure relief valve hose
• Coolant supply and return hoses.

Remove the ignition control module.

Refer to Procedure 019-105, in the B Gas Plus, B LPG Plus, and C Gas Plus Fuel System Troubleshooting and Repair Manual, Bulletin 4021317.

Remove the mounting capscrews from the evaporator mounting brackets.

Remove the evaporator assembly.

Remove the following components from the evaporator assembly:

• Mounting brackets
• Fuel outlet hose (Discard the sealing washer.)
• Fuel shutoff valve (If equipped with an externally mounted valve at the fuel inlet.)

Remove the following components from the evaporator assembly:

• Fuel pressure sensor adaptor
• Fuel transfer hose
• Mounting brackets
• Fuel outlet hose (Discard the sealing washer.)
• Fuel shutoff valve.

Install the following components on the new evaporator:

• Mounting brackets

• Fuel outlet hose

A new sealing washer must be used.

• Fuel shutoff valve into the fuel inlet connection.

Install the following components on the new evaporator:

• Mounting brackets

• Fuel pressure sensor adaptor

• Fuel outlet hose

A new sealing washer must be used.

• Fuel shutoff valve into the fuel inlet connection
• Fuel transfer hose.

Install the capscrews to mount the evaporator to the retaining brace or ignition module bracket.

The coolant line that is attached at the thermostat housing connects to the rear fitting of the evaporator.

Connect the following:

• Coolant supply and return lines

• Relief valve line. Replace the crush washer

• Fuel supply line at the fuel filter housing

• Fuel supply line from the magnetic in-line filter at the inlet port.

Port Identification

1. Fuel outlet port
2. Coolant inlet port
3. Coolant outlet port
4. Fuel inlet fitting.

Connect the following electrical connections:

• Fuel shutoff valve.

WARNING  Liquefied petroleum gas is normally treated with an odor-producing chemical, so that users will be able to smell gas leaks. Always be alert for the smell of gas. If you enter a room or approach a vehicle and a smell of gas is present, immediately shut off all engines and ignition sources and avoid sparks, arcing switches and equipment, cigarettes, pilot lights, flames, and other sources of ignition in the area and in areas with common ventilation. Provide extra ventilation to the area and do not start the equipment or nearby equipment until the leak is corrected and the area is ventilated. Avoid leaving liquefied petroleum gas-fueled equipment in unvented rooms overnight or for extended periods. Store and service liquefied petroleum gas-fueled equipment in large, well-ventilated areas or outside.

WARNING  Liquefied petroleum gas is heavier than air and can accumulate near the floor, in sumps, and in low-lying areas.

Turn on the vehicle main fuel supply valve.

Start the engine and let idle for one minute.

Shut the engine off.

Combustible Gas Detector, Part Number 3823984

Turn the ignition keyswitch to the ON position only (do not engage the starting motor) and check all connections for gas leaks using a gas detector, Part Number 3823984, or a soap solution.

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

Install the capscrews to mount the evaporator to the retaining brace or ignition module bracket.

The coolant line that is attached at the thermostat housing connects to the rear fitting of the evaporator.

Connect the following:

• Coolant supply and return lines

• Relief valve line. Replace the crush washer

• Fuel supply line at the fuel filter housing

• Fuel supply line from the magnetic in-line filter at the inlet port.

Port Identification

1. Fuel outlet port
2. Coolant inlet port
3. Coolant outlet port
4. Fuel inlet fitting.

Connect the following electrical connections:

• Fuel shutoff valve
• Primary fuel pressure sensor.

Install the ignition control module.

Refer to Procedure 019-105, in the B Gas Plus, B LPG Plus, and C Gas Plus Fuel System Troubleshooting and Repair manual, Bulletin 4021317.

WARNING  Liquefied petroleum gas is normally treated with an odor-producing chemical, so that users will be able to smell gas leaks. Always be alert for the smell of gas. If you enter a room or approach a vehicle and a smell of gas is present, immediately shut off all engines and ignition sources and avoid sparks, arcing switches and equipment, cigarettes, pilot lights, flames, and other sources of ignition in the area and in areas with common ventilation. Provide extra ventilation to the area and do not start the equipment or nearby equipment until the leak is corrected and the area is ventilated. Avoid leaving liquefied petroleum gas-fueled equipment in unvented rooms overnight or for extended periods. Store and service liquefied petroleum gas-fueled equipment in large, well-ventilated areas or outside.

WARNING  Liquefied petroleum gas is heavier than air and can accumulate near the floor, in sumps, and in low-lying areas.

Turn on the vehicle main fuel supply valve.

Start the engine and let idle for one minute.

Shut the engine off.

Combustible Gas Detector, Part Number 3823984

Turn the ignition keyswitch to the ON position only (do not engage the starting motor) and check all connections for gas leaks using a gas detector, Part Number 3823984, or a soap solution.

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

NOTE: It is possible to see pressure spikes exceed 207 kPa [30 psi] during a throttle “snap” event, but they should never remain above 207 kPa [30 psi].

Check fuel pressures:

• Check fuel pressure on the OEM side. This pressure should never fall below 241 kPa [35 psi] or rise above 1724 kPa [300 psi at coolant temperatures above 21°C [70°F].
• Check fuel pressure on the engine side. This pressure will vary depending on the engine coolant temperature. At coolant temperatures below 21°C [70°F], the pressure is regulated to approximately 103 kPa [15 psi].
• This pressure should slowly increase to 131 to 207 kPa [19 to 30 psi] as the coolant temperature increases at idle. Under full load with the coolant temperature at rated conditions, the pressure can drop to 131 to 172 kPa [19 to 25 psi].

NOTE: It is possible to see pressure spikes exceed 276 kPa [40 psi] during a throttle “snap” event, but they should never remain above 276 kPa [40 psi].

Check fuel pressures:

• Use INSITE™ to check fuel pressure (fuel pressure sensor, primary) on the original equipment manufacturer (OEM) side. This pressure should never fall below 276 kPa [40 psi] or rise above 1724 kPa [300 psi] at coolant temperatures above 21°C [70°F].
• Use INSITE™ to check the fuel pressure (fuel pressure sensor, secondary). This pressure will vary depending on the engine coolant temperature. At coolant temperatures below 21°C [70°F], the pressure is regulated to approximately 145 kPa [21 psi].
• This pressure should slowly increase to 159 to 221 kPa [23 to 32 psi] as the coolant temperature increases at idle. Under full load with the coolant temperature at rated conditions, the pressure can drop to 172 to 193 kPa [25 to 28 psi].