Fuel Pressure Check

Fuel Pressure Check

Special Tool

(A): 09912-58442

(B): 09912-58432

(C): 09912-58490










System Description

Fuel pressure regulator keeps the fuel pressure applied to injector 290 kPa higher than that in intake manifold at all times.

Troubleshooting

NOTE:

Before using the following table, check to make sure that battery voltage is higher than 11 V. If battery voltage is low, pressure becomes lower than specification even if fuel pump and line are in good condition.

1.
Check fuel pressure (Refer to Fuel Pressure Inspection Fuel Pressure Inspection
for details).
Release fuel pressure from fuel feed line.
Install fuel pressure gauge.
Check fuel pressure by repeating ignition switch ON and OFF.

Is fuel pressure then 270 - 310 kPa (2.7 - 3.1 kg/cm², 38.4 - 44.0 psi)?
YES
Go to Step 2.
NO
Go to Step 5.

2.
Is 200 kPa (2.0 kg/cm², 28.4 psi) or higher fuel pressure retained for 1 minute after fuel pump is stopped at Step 1?
YES
Go to Step 3.
NO
Go to Step 4.

3. Check fuel pressure regulator for operation.

Start engine and warm it up to normal operating temperature.
Keep it running at specified idle speed.

Is fuel pressure then within 220 - 260 kPa (2.2 - 2.6 kg/cm², 31.3 - 36.9 psi)?
YES
Normal fuel pressure.
NO
Clogged vacuum passage for fuel pressure regulator or faulty fuel pressure regulator.

4.
Is there fuel leakage from fuel feed line hose, pipe or their joint?
YES
Fuel leakage from hose, pipe or joint.
NO
Go to Step 10.

5.
Was fuel pressure higher than spec. in Step 1?
YES
Go to Step 6.
NO
Go to Step 7.

6. Disconnect fuel return hose from fuel pressure regulator and connect new return hose to it.
Put the other end of new return hose into approved gasoline container.
Operate fuel pump.

Is specified fuel pressure obtained then?
YES
Restricted fuel return hose or pipe.
NO
Faulty fuel pressure regulator.

7.
Was no fuel pressure applied in Step 1?
YES
Go to Step 8.
NO
Go to Step 9.

8.
With fuel pump operated and fuel return hose blocked by pinching it, is fuel pressure applied?
YES
Faulty fuel pressure regulator.
NO
Shortage of fuel or fuel pump or its circuit malfunction (refer to Fuel Pump Circuit Check Fuel Pump Circuit Check
).

9. Operate fuel pump.
With fuel return hose blocked by pinching it, check fuel pressure.

Is it 450 kPa (4.5 kg/cm², 63.9 psi) or more?
YES
Faulty fuel pressure regulator.
NO
Clogged fuel filter, restricted fuel feed hose or pipe, faulty fuel pump or fuel leakage from hose connection in fuel tank.

10. Disconnect fuel return hose from pressure regulator and connect new return hose to it.
Insert the other end of new return hose into approved gasoline container.
Check again if specified pressure is obtained.

While doing so, does fuel come out of return hose?
YES
Faulty fuel pressure regulator.
NO
Fuel leakage from injector, fuel leakage from between injector and delivery pipe, faulty fuel pump (faulty check valve in fuel pump) or fuel leakage from fuel pressure regulator diaphragm.