Operation CHARM: Car repair manuals for everyone.
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Fuel Pressure: Testing and Inspection

Pressure Gauge Connection:





- Check that the battery voltages is above 12 volts.
- Disconnect the cable from the negative (-) terminal of the battery.

CAUTION: With Airbag, work must be started after approx. 30 seconds or longer from the time the ignition switch is turned to the LOCK position and the negative (-) terminal cable is disconnected from the battery.

- Put a suitable container or shop towel under the fuel filter.
- Remove the union bolt and two gaskets, and disconnect the fuel in let hose from the fuel filter outlet.

- Install the fuel inlet hose and pressure gauge to the fuel filter outlet with three new gaskets and the union bolt.


Torque: 29 N.m (300 kgf.cm, 22 ft.lbs)

- Wipe off any splattered gasoline.
- Reconnect the battery negative (-) cable.

Installing Jumper Wire:






- Using a jumper wire, connect terminals +B and FP of the check connector.
- Turn the ignition switch ON.

Reading Pressure Gauge:





- Measure the fuel pressure.

Fuel pressure:
265-304 kPa (2.7-3.1 kgf/cm2, 38-44 psi)


- If pressure is high, replace the fuel pressure regulator.
- If pressure is low, check the following parts:

^ Fuel hoses and connections
^ Fuel pump
^ Fuel filter
^ Fuel pressure regulator



- Start the engine.

Checking Fuel Pressure - No Vacuum To Regulator:





- Disconnect the vacuum sensing hose from the air intake chamber and plug the air intake chamber outlet.
- Measure the fuel pressure at idling.

Fuel pressure:
265-304 kPa (2.7-3.1 kgf/cm2, 38-44 psi)


Checking Fuel Pressure - Vacuum To Regulator:





- Reconnect the vacuum sensing hose to the air intake chamber.
- Measure the fuel pressure at idling.

Fuel pressure:
206-255 kPa (2.1-2.6 kgf/cm2, 31-37 psi)


- If pressure is not as specified, check the vacuum sensing hose and fuel pressure regulator.
- Stop the engine.
- Check that the fuel pressure remains 147 kPa (1.5 kgf/cm2, 21 psi) or more for 5 minutes after the engine is turned off.
- If pressure is not as specified, check the fuel pump, pressure regulator and/or injector.
- After checking fuel pressure, disconnect the battery negative (-) cable and carefully remove pressure gauge to prevent gasoline from splashing.
- Connect the fuel inlet hose with two new gaskets and the union bolt.

Torque: 29 N.m (300 kgf.cm, 22 ft.lbs)