Pressure release
Before disconnecting fuel hoses and lines, relieve pressure from the system by loosening the service bolt at the top of the fuel filter.
Do not smoke while working on the fuel system. Keep open flames and sparks away from your work area.
When relieving fuel pressure, make sure the ignition switch is turned off.
1. Disconnect the negative battery cable from the negative terminal of the battery.
2. Remove the fuel tank cap.
3. Place a box wrench on the service bolt on the fuel filter while holding the service bolt with another wrench.
4. Cover the service bolt with a rag or paper towel.
5. Slowly loosen the service bolt one full turn.
Note:
- A fuel pressure gauge can be attached to the service bolt hole.
- Always replace the seal between the service bolt and the special bolt whenever you loosen the service bolt.
- When removing bolts, always replace all seals with new ones.
Inspection
1. Relieve fuel pressure.
2. Remove the service bolt on the fuel filter while holding the special bolt with another wrench. Attach a special key.
3. Start the engine. Measure fuel pressure with the engine idling and the fuel pressure regulator vacuum hose disconnected from the fuel pressure regulator and pinched.
The pressure should be:
- engine D15Z6, D1527: 226-275 kPa (2.3-2.8 kgf/cm2)
- engine D16У7, D16Y6, D16Y8: 265-314 kPa (2.7-3.2 kgf/cm2)
- engine A16A2, V16A4, V16A5, V16A6: 275-324 kPa (2.8-3.3 kgf/cm2)
4. Connect the vacuum hose to the fuel pressure regulator.
The pressure should be:
- engine D15Z6, D15Z7: 162-211 kPa (1.65-2.15 kgf/cm2)
- engines D16Y7, D16Y6, D16Y5, D16Y8: 196-245 kPa (2.6-2.5 kgf/cm2)
- engines A16A2, V16A4, V16A5, V16A6: 196-245 kPa (2.0-2.5 kgf/cm2)
If the engine does not start, turn the ignition switch ON (fl), wait 2 s, turn it off, then turn it on again and look at the fuel pressure readings,
If the fuel pressure is not within specification, check the fuel pump first. IF the fuel pump is OK, check the following:
If the fuel pressure is higher than specified, inspect:
- The fuel return line and hose are pinched or clogged,
- The fuel pressure regulator is faulty.
If fuel pressure is below specification, inspect:
- The fuel filter is clogged.
- The fuel pressure regulator is faulty.
- Leaking in the fuel line.