Fuel Delivery and Air Induction: Service and Repair

NOTE: A certain amount of air becomes trapped in the fuel system when fuel system components are serviced or replaced. Bleed the system after fuel system service according to the following procedures.

WARNING: Do not bleed air from the fuel system of a hot engine. Do not allow fuel to spray onto the exhaust manifold when bleeding air from the fuel system.

MANUAL BLEEDING
Some air enters the fuel system when the filters or injection pump supply line are changed. This small amount of air is vented automatically from the injection pump through the fuel drain manifold. This is if the filter was changed according to instructions.

The system may have to be bled manually if:
- The vehicle fuel tank has been allowed to run empty
- The fuel filter is not filled before installation
- The fuel injection pump is replaced
- High-pressure fuel line connections are loosened or lines replaced
- Initial engine start-up or start-up after an extended period of no engine operation.

1. Loosen the low-pressure bleed bolt.
2. Operate the rubber push-button primer on the fuel transfer pump. Do this until the fuel exiting the low-pressure bleed bolt is free of air.
3. Tighten low-pressure bleed screw to 8 N.m (6 ft. lbs.) torque.






FUEL INJECTION PUMP BLEEDING

WARNING: The engine may start when cranking to bleed air from the injection pump place the transmission in neutral or park and set parking brake before engaging the starter motor.

CAUTION: Do not engage the starter motor for more than 30 seconds at a time. Allow two minutes between cranking intervals.

1. Perform the previous procedure: Manual Bleeding.
2. Crank the engine for 30 seconds at a time to allow air trapped in the injection pump to vent out the drain manifold.
- Observe the previous WARNING and CAUTION.

HIGH-PRESSURE FUEL LINE BLEEDING

WARNING: The fuel injection pump supplies high-pressure fuel of as high as 120,000 kPa (17,405 psi) to each individual injector through the high-pressure lines. Fuel under this amount of pressure can penetrate the skin and cause personal injury. Wear safety goggles and adequate protective clothing and avoid contact with fuel spray when bleeding high- pressure fuel lines.

WARNING: Do not bleed air from the fuel system of a hot engine. Do not allow fuel to spray onto the exhaust manifold when bleeding air from the fuel system.

Bleed air from one injector at time.

1. Loosen the high-pressure fuel line fitting at the injector.






2. Crank the engine until all air is bled from the line.
- Do not operate the starter motor for longer than 30 seconds.
- Wait two minutes between cranking intervals.
3. Start the engine and bleed one injector at a time until the engine runs smoothly.
4. Tighten fuel line(s) at injector(s) to 30 N.m (22 ft. lbs.) torque.