Fuel Delivery and Air Induction: Testing and Inspection
FUEL SYSTEM LEAK TESTCombustible Gas Detector:
SPECIAL TOOL(S)
Fuel Injection Supply Manifold and Fuel Injectors
1. NOTE: After the vehicle has soaked for several hours, a very slight natural gas smell may emanate from within the intake manifold and intake air system. This is normal, as the fuel injectors leak down from the fuel injection supply manifold to the intake manifold over several hours.
Remove the fuel pump relay from the power distribution box.
2. Construct a jumper wire from 152 mm (6 inches) of 18 gauge wire and two spade terminal ends.
3. Jumper the fuel pump relay circuit from Socket 87 to Socket 30.
4. Remove the jumper wire.
5. Install the fuel pump relay into the power distribution box.
6. Check the spring lock coupling and the fuel injection supply manifold to fuel injector connections for leaks, using the combustible gas detector.
7. If a leak is detected, verify the connection is engaged properly, then retest.
8. If the leak remains, repair as necessary and retest.
Fuel Tanks, Filter and Lines
1. NOTE: Verify system pressure is at least 10,343 kPa (1500 psi). If system pressure is below 10,343 kPa (1500 psi), refuel the vehicle.
Check the fuel tank(s), coalescer/filter and fuel line connections for leaks, using the combustible gas detector.
2. If a leak is detected, verify that the fittings are tightened properly, then retest.
3. If the leak remains, inspect the O-ring seal, O-ring seal land and sealing surfaces for any damage, distortion or contamination.
4. Repair as necessary and retest.