Relieving fuel pressure
1. Remove the fuel pump fuse located in the IPDM E/R unit.
2. Start the engine.
3. After the engine stalls, crank it two or three times and relieve all fuel pressure.
4. Turn the ignition key to position «OFF».
5. After servicing the fuel system, replace the fuel pump fuse.
Checking fuel pressure
Attention:
- To avoid danger, relieve fuel pressure before disconnecting the fuel line.
- The method of connecting the fuel hoses when checking the fuel pressure should not be used for other purposes.
- When performing maintenance, be careful not to scratch or get foreign particles into the connection area so that the quick-release fitting maintains a tight seal with the internal O-rings.
- Do not check fuel pressure while electrical equipment is running (e.g. headlights, rear window defroster, air conditioning, etc.). Due to fluctuations in engine load and changes in manifold pressure, the fuel pressure gauge may give unreliable readings.
Note. Place a tray under the disconnected fuel line because fuel may leak from it. It is impossible to completely relieve the fuel pressure, because Models of the T31 series do not have a fuel removal system.
1. Reduce fuel pressure to zero.
2. To check the fuel pressure, prepare the fuel hose «IN» and fuel pipe adapter «D» (special tool: KV10118400), then connect the fuel gauge «A».
- Use a suitable fuel hose to check fuel pressure (branded NISSAN fuel hose without quick-release fitting).
- To avoid stretching the hose when testing, use a moderately long piece.
- Do not use the fuel pressure test hose if it is damaged or cracked.
- Check the fuel pressure with a pressure gauge.
3. Disconnect the fuel hose.
- Do not twist or bend the fuel hose as it is made of plastic.
4. Connect the fuel hose (1) to check the fuel pressure to the fuel pipe (from the engine side) using a clamp (2) as shown in the picture.
Bead No. 2 (5)
- Wipe off any oil or dirt from the connecting section of the hose using a rag soaked in gasoline.
- Apply the required amount of gasoline between the top of the fuel pipe (3) and shoulder No. 1 (4).
- Push the fuel hose until it contacts collar #1 on the fuel pipe.
- Use a genuine NISSAN clamp (Catalog No. 16439 N4710 or 16439 40U00).
- When connecting the fuel line next time, install new clamps/
- Tighten the clamps with a torque screwdriver.
- Place the clamp at a distance of 1-2 mm from the edge of the hose.
: 1-1.5 Nm (0.1- 0.15 kg-m)
- Make sure the clamp screw does not touch adjacent components.
5. Connect the fuel pipe adapter to the quick connect fitting.
A. Fuel pressure gauge; B. Fuel hose
6. After connecting the fuel hose, pull it with a force of about 98 N (10 kg) and make sure it doesn't come off the tube.
7. Turn the ignition key to position «ON» and check for fuel leaks.
8. Start the engine and check for fuel leaks.
9. Take readings from the fuel pressure gauge.
Do not check fuel pressure with the engine running. The fuel pressure gauge may give unreliable readings.
When checking fuel pressure, check for fuel leaks at the joints every 3 minutes.
At idle speed:
approx. 350 kPa (3.57 kg/cm²)
10. If the result is unsatisfactory, proceed to the next step.
11. Check the following:
- whether the fuel hoses and tubes are clogged;
- Is the fuel filter clogged?
- fuel pump;
- Is the fuel pressure regulator clogged?
If everything is OK, replace the fuel pressure regulator. If there are deficiencies, eliminate them or replace the component.