While In the Workshop
Special Tools:^ 981 2270
^ 981 2273
^ 981 2282
^ 998 9725
^ 999 5011
^ 999 5479
^ 999 5843
Checking Vacuum Hose to Pressure Regulator
- Disconnect vacuum hose from pressure regulator.
- Check that the hose is not blocked by blowing into it.
If the hose is OK:
^ Proceed to: Connecting Pressure Gauge section below.
If the hose is blocked:
^ Check hose and connector on the intake manifold, clean/replace.
Connecting Pressure Gauge
- Supplement pressure gauge 999 5011 with nipple 998 9725 and adapter 999 5479 before use.
- Remove safety cap from valve on fuel rail.
- Connect adapter to the valve in its locked position (illustration 1 valve closed).
- Turn cock on pressure gauge 999 5011 to position 3 (the cock should point toward the adapter 999 5479).
- Unlock adapter (illustration 2 valve open).
- Continue with: Starting Fuel Pump.
Starting Fuel Pump
- Remove fuel pump (FP) relay position 2 in the integrated relay/fusebox on the left of the dashboard.
- Connect jumper cable across relay base terminals 1 and 3.
- Switch ON ignition, fuel pump should start.
- Continue with: Measuring Line Pressure.
Measuring Line Pressure
- Read off line pressure from pressure gauge.
- Line pressure should be 300 kPa (3.0 kp/cm2) (42.6 psi).
If line pressure is OK:
^ Proceed to: Checking Fuel Filter section below.
If line pressure is too low:
^ Proceed to: Line Pressure Too Low section below.
If line pressure is too high:
^ Proceed to: Line Pressure Too High section below.
Line Pressure Too Low
- Squeeze the return line and check if the pressure rises.
CAUTION: Do not allow pressure to exceed 600 kPa (85.3 psi).
If pressure rises:
^ Pump and lines OK. Try a new pressure regulator. Then measure line pressure. Proceed to: Measuring Line Pressure section above.
If pressure does not rise:
^ Check filter gauze at fuel pump. If the filter gauze is OK: replace fuel pump. Then measure line pressure. Proceed to: Measuring Line Pressure section above.
Line Pressure Too High
- Disconnect jumper cable between relay base terminals 1 and 3.
- Disconnect return line from pressure regulator. Blow into line.
If the cable is OK:
^ Try a new pressure regulator. Then measure line pressure. Proceed to: Measuring Line Pressure section above.
If the line is blocked:
^ Check if the return line is blocked, clean/replace. Then measure line pressure. Proceed to: Measuring Line Pressure section above.
Checking Fuel Filter
- Squeeze the return line and check is the pressure rises.
CAUTION: Do not allow pressure to exceed 600 kPa (6.0 kp/cm2)(85.3 psi).
If pressure rises rapidly:
^ Proceed to: Checking Pressure Regulator, Lowering Pressure section below.
If pressure rises slowly:
^ Replace fuel filter.
Checking Pressure Regulator, Lowering Pressure
- Connect vacuum pump 999 5843 to pressure regulator.
- Pump air out of regulator.
- Check that line pressure rises by the same amount as the pressure in the regulator drops. 300 kpa (42.6 psi) - negative pressure = line pressure.
- Disconnect hose from pressure tester. Line pressure should return to 300 kPa (42.6 psi).
If pressure is OK:
^ Proceed to: Checking Pressure Regulator, Increasing Pressure section below.
If pressure is NOT OK:
^ Replace pressure regulator.
Checking Pressure Regulator, Increasing Pressure
- Connect pressure tester 998 5496 and manometer 999 5230 to pressure regulator.
- Pump up the pressure in the regulator.
- Check that line pressure rises by the same amount as the pressure in the regulator. 300 kpa (42.6 psi) - negative pressure = line pressure.
- Disconnect hose from pressure tester. Line pressure should return to 300 kPa (42.6 psi).
If pressure is OK:
^ Proceed to: Checking Residual Pressure section below.
If pressure is NOT OK:
^ Replace pressure regulator.
Checking Residual Pressure
- Switch off ignition between terminals 1 and 3 on the relay base.
- Reinstall fuel pump relay.
NOTE: The value must not drop below 200 kPa (28.5 psi) in less than 20 minutes.
If the residual pressure is OK:
^ Proceed to: Disconnecting Pressure Gauge section below.
If residual pressure is NOT OK:
^ Fault may be due to leakage from injectors, connections, fuel pump non-return valve or lines. Repair as necessary.
Disconnecting Pressure Gauge
- Ignition off.
- Start draining unit.
- Turn pressure gauge cock to mid-position.
- Lock adapter (valve closed as in picture 1).
- Disconnect adapter from valve.
- Stop draining unit.
- Reinstall equipment.
CAUTION: Remember to reinstall valve safety cap.