With Federal Emissions (Emissions Code D3)

FUEL PRESSURE AND RESIDUAL PRESSURE TESTING





Checking the Fuel Pump Relay's Two-stage Function
^ Switch Ignition OFF.
^ Remove fuse no. 2.
^ Connect an amp meter between fuse no. 2's connectors in the fuse-holder.





^ START the engine.
^ Rev. the engine, at speeds above 3000 rpm, the current consumption should be higher than at engine speeds below 3000 rpm.

If current consumption increases at 3000 rpm:
- The fuel pump relay's two-stage function is OK.
- Check the vacuum hose leading to the pressure regulator.
If current consumption does not increase at 3000 rpm:
- Check at full-speed.
- Proceed to: CHECKING FULL SPEED section below.





Checking Vacuum Hose to Pressure Regulator
^ Remove throttle pulley cover.
^ Disconnect vacuum hose from pressure regulator.
^ Check for blockage by blowing through hose.

If hose is clear:
- Connect pressure gauge.
If hose is blocked:
- Check hose and connection at intake manifold.
- Clean or replace as required.





Connect Pressure Gauge
^ Fit pressure gauge P/N 9995011 using union P/N 9989725 and adapter P/N 9995479.
^ Connect adapter to valve on fuel distribution manifold, with adapter in locked position (i.e. valve closed).
^ Turn pressure gauge cock towards adapter P/N 9995479.
^ Connect other gauge connection to fuel drainage unit P/N 9812270, P/N 9812273 and P/N 9812282.
^ Unlock adapter (i.e. valve open).
^ Continue with START FUEL PUMP section below.





Start Fuel Pump
^ Remove electrical distribution unit cover.
^ Remove fuel pump relay (position 103 in electrical distribution unit).
^ Connect jumper lead across relay base terminals 1 and 3.
^ Switch ignition ON. Fuel pump should start.
^ Continue with MEASUREMENT OF SYSTEM PRESSURE section below.





Measurement of System Pressure
^ Read system pressure on pressure gauge.

System pressure should be 300 kPa (43.5 psi).

If reading is correct:
- Proceed to: CHECKING THE FUEL FILTER section below.
If reading is too high:
- Proceed to: SYSTEM PRESSURE TOO HIGH section below.
If reading is too low:
- Proceed to: SYSTEM PRESSURE TOO LOW section below.





System Pressure Too High
^ Disconnect jumper lead across relay base terminals 1 and 3.
^ Disconnect return line from pressure regulator.
^ Blow through line towards tank.

If line is clear:
- Try with new pressure regulator and measure system pressure again.
If line is blocked:
- Check for blockage in return line and clean or replace as required. Measure system pressure again.





System Pressure Too Low
^ Clamp return line and check if pressure rises.

CAUTION: Do not allow pressure to exceed 600 kPa (87 psi).

If pressure rises:
- Pump and lines are intact.
- Replace pressure regulator and measure system pressure again.
If pressure does not rise:
- Check the strainer at the fuel pump.
If fuel pump strainer is OK:
- Replace the fuel pump and measure system pressure again.





Checking the Fuel Filter
^ Squeeze the return pipe and check it the pressure rises.

CAUTION: Do not let the pressure rise higher than 600 kPa (87 psi).

If the pressure rises quickly:
- Check the pressure regulator.
- Proceed to : CHECKING PRESSURE REGULATOR, PRESSURE REDUCTION section below.
If the pressure rises slowly:
- Replace the fuel filter.





Checking Pressure Regulator, Pressure Reduction
^ Connect vacuum pump P/N 9995843 to pressure regulator.
^ Purge the regulator.
^ Check that system pressure falls by same amount as regulator pressure.

300 kPa (43.5 psi) - vacuum = system pressure

^ Disconnect hose from vacuum pump.

System pressure should return to 300 kPa (43.5 psi).

If the pressure is OK:
- Check the pressure regulator.
- Proceed to: PRESSURE REGULATOR, INCREASE IN PRESSURE section below.
If the pressure is not OK:
- Replace the pressure regulator.





Checking the Pressure Regulator, Increase in Pressure
^ Connect pressure tester P/N 9985496 and manometer P/N 9995230 to the pressure regulator.
^ Pump up the pressure in the regulator.
^ Check that system pressure rises as much as the increased pressure in the regulator.

300 kPa (43.5 psi) + overpressure = system pressure

^ Disconnect the hose from the pressure tester.

System pressure should return to 300 kPa (43.5 psi).

If the pressure regulator is OK:
- Check the residual pressure.
If the pressure regulator is not OK:
- Replace the pressure regulator.





Checking Residual Pressure
^ Switch ignition OFF.
^ Disconnect jumper lead between relay base terminals 1 and 3.
^ Reinstall fuel pump relay.

System pressure must not fall below 200 kPa (29 psi) in less than 20 minutes.

If pressure is correct:
- Proceed to: DISCONNECTION OF PRESSURE GAUGE section below.
If pressure is incorrect:
- Fault may be due to leakage from injectors, connections, fuel pump non-return valve or lines.
- Repair as required.





Disconnection of Pressure Gauge
^ Switch ignition OFF.
^ START drainage unit.
^ Turn pressure gauge cock to mid-position.
^ Lock adapter (i.e. valve closed).
^ Disconnect adapter from valve.
^ Stop drainage unit.
^ Reinstate equipment.

NOTE: Remember to refit valve safety cap.





Checking Full-speed
^ Switch Ignition OFF.
^ Remove the cover from the central electrical unit.
^ Remove the fuel pump relay (pos. 103 in the central electrical unit)
^ Connect a lead between the relay connector 1 and 3.
^ Switch Ignition ON.





^ Check that the fuel pump is working by gently squeezing the hose leading to the fuel pressure regulator.

A slight pulsating sensation is felt if the fuel pump is working.

If the fuel pump works:
- Check half-speed.
If the fuel pump does not work:
- Check the lead between the fuel pump relay connector 3 and the fuel pump connector 1 for signs of a break.





Checking Half-speed
^ Switch Ignition OFF.
^ Remove the lead linking connector 1 and 3 on the fuel pump relay connector.
^ Connector the lead between the relay coupling's connector 1 and 5.
^ Switch Ignition ON.





^ Check that the fuel pump is working by gently squeezing the hose leading to the fuel pressure regulator.

A slight pulsating sensation is felt if the pump is working.

If the fuel pump works:
- Test with a new fuel pump relay.
If the fuel pump does not work:
- Check the lead between the relay and series resistance.





Check the Lead Between the Relay and the Series Resistance
^ Switch Ignition OFF.
^ Remove the windshield wiper arms.
^ Remove the plenum cover.
^ Disconnect the series resistance.
^ Connect the lead between relay coupling connectors 1 and 5.
^ Switch Ignition ON.





^ Connect a voltmeter between the series resistance's connector 2 (to fuel pump relay) and ground.

The voltmeter should show battery voltage.

If the reading is OK:
- Check the series resistance.
If the value differs:
- Check the lead between the fuel pump relay connector 5 and the series resistance, connector 2, for signs of a break.





Check the Series Resistance
^ Switch Ignition OFF.
^ Series resistance disconnected.
^ Connect an ohmmeter between the series resistance's connectors 1 and 2 (to series resistance).

The ohmmeter should show approx. 0.9 ohms.

If the reading is OK:
- Check the lead between the series resistance connector 1 and fuel pump connector 1 for signs of a break.
If the reading differs:
- Test with a new series resistance.