Checking Fuel Pressure and Residual Pressure
Checking fuel pressure and residual pressure
981 2270 PUMP TROLLEY 981 2270 Pump Trolley
981 2273 PUMP 981 2273 Pump
981 2282 Tank 981 2282 Tank
998 9725 Adapter 998 9725 Adapter
999 5011 MANOMETER 999 5011 Manometer
999 5479 ADAPTER 999 5479 Adapter
999 5843 VACUUM PUMP AT 999 5843 Vacuum Pump AT
998 5496 ENGINE COOLANT SYSTEM - PRESSURE TESTER 998 5496 Engine Coolant System - Pressure Tester
999 5230 PRESSURE METER 999 5230 Pressure Meter
Choosing a method for taking a reading
It is possible to measure fuel pressure with the car stationary or while being driven. Residual pressure is measured with the car stationary.
Continue - Checking vacuum hose to pressure regulator
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Checking vacuum hose to pressure regulator
- Ignition off.
- Remove throttle pulley cover.
- Disconnect vacuum hose from pressure regulator.
- Check that the hose is not blocked by blowing into it.
Is the hose OK?
Yes - Connect pressure gauge
No - Checking hose and connection
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Checking hose and connection
- Check hose and terminal on intake manifold, clean/replace.
Continue - Verification
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Connect pressure gauge
- Supplement pressure gauge 999 5011 MANOMETER 999 5011 Manometer with nipple 998 9725 Adapter 998 9725 Adapter and adapter 999 5479 ADAPTER 999 5479 Adapter before use.
- Connect adapter to valve on fuel rail, with adapter in locked position (valve closed as in picture 1).
- Turn pressure gauge cock so it faces adapter 999 5479 ADAPTER 999 5479 Adapter.
- Connect other pressure gauge connector to fuel draining unit 981 2270 PUMP TROLLEY 981 2270 Pump Trolley , 981 2273 PUMP 981 2273 Pump and 981 2282 Tank 981 2282 Tank.
- Unlock adapter (illustration 2 valve open).
Continue -Starting fuel pump (FP)
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Starting fuel pump (FP)
- Remove central electrical unit cover.
- Remove fuel pump relay (position 103 in electrical distribution unit).
- Connect a cable between relay base terminals 1 and 3.
- Ignition on.
Fuel pump (FP) should operate.
Continue - Measuring line pressure
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Measuring line pressure
- Read off line pressure from pressure gauge.
Line pressure should be 300 kPa (3.0 kp/cm2).
OK - Checking fuel filter
Low - Line pressure too low
High - Line pressure too high
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Line pressure too high
- Ignition off.
- Remove the cable between the relay base terminals 1 and 3.
- Disconnect return line from pressure regulator.
- Blow through the line into the fuel tank.
Is cable OK?
Yes - Stop fuel pump
No - Checking for blockage
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Stop fuel pump
- Switch off ignition.
- Disconnect jumper lead between relay base terminals 1 and 3.
Press Continue.
Continue - Replacing component
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Replacing component
Try a new pressure regulator.
Continue - Connect pressure gauge
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Checking for blockage
- Check if there is a blockage in the return line. Clean and replace as necessary.
Continue - Connect pressure gauge
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Starting fuel pump (FP)
- Remove central electrical unit cover.
- Remove fuel pump relay (position 103 in electrical distribution unit).
- Connect a cable between relay base terminals 1 and 3.
- Ignition on.
Fuel pump (FP) should operate.
Continue - Measuring line pressure
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Measuring line pressure
- Read off line pressure from pressure gauge.
Line pressure should be 300 kPa (3.0 kp/cm2).
OK - Stop fuel pump
Not OK - Fault-tracing information
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Line pressure too low
Caution! Do not allow pressure to exceed 600 kPa (6.0 kPa/cm2).
- Squeeze the return line and check is the pressure rises.
Did the pressure increase?
Yes - Replacing component
No - Check filter gauze at fuel pump (FP). If it is OK: Replace pump according to Fuel pump, replacement Fuel Pump, Replacement and then measure line pressure.
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Replacing component
Try a new pressure regulator
Continue - Connect pressure gauge
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Checking for blockage
- Check filter gauze at fuel pump (FP). If it is OK: Replace fuel pump (FP) according to Fuel pump, replacement Fuel Pump, Replacement
Continue - Connect pressure gauge
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Checking fuel filter
Caution! Do not allow pressure to exceed 600 kPa (6.0 kPa/cm2).
- Squeeze the return line and check if pressure increases quickly or slowly.
Did the pressure increase quickly?
Yes - Checking pressure regulator, pressure reduction
No - Replacing component
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Replacing component
- Replace fuel filter Removal and Replacement.
Continue - Start fuel pump
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Start fuel pump
- Connect jumper lead across relay base terminals 1 and 3.
- Switch on ignition.
Fuel pump should run.
Continue - Checking fuel filter
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Checking fuel filter
Caution! Do not allow pressure to exceed 600 kPa (6.0 kPa/cm2).
- Squeeze the return line and check if pressure increases quickly or slowly.
Did the pressure increase quickly?
Yes - Stop fuel pump
No - Fault-tracing information
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Checking pressure regulator, pressure reduction
- Connect vacuum pump 999 5843 VACUUM PUMP AT 999 5843 Vacuum Pump AT to pressure regulator.
- Pump air out of the regulator.
- Check that line pressure drops by the same amount as the pressure in the regulator drops.
- 300 kpa - negative pressure = line pressure
- Disconnect the hose from the vacuum pump.
Line pressure should return to 300 kPa.
OK - Checking pressure regulator, pressure increase
Not OK - Replacing component
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Replacing component
Try a new pressure regulator.
Continue - Checking pressure regulator, pressure reduction
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Checking pressure regulator, pressure reduction
- Connect vacuum pump 999 5843 VACUUM PUMP AT 999 5843 Vacuum Pump AT to pressure regulator.
- Pump air out of the regulator.
- Check that line pressure drops by the same amount as the pressure in the regulator drops.
- 300 kpa - negative pressure = line pressure
- Disconnect the hose from the vacuum pump.
Line pressure should return to 300 kPa.
OK - Stop fuel pump
Not OK - Fault-tracing information
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Checking pressure regulator, pressure increase
- Connect pressure tester 998 5496 ENGINE COOLANT SYSTEM - PRESSURE TESTER 998 5496 Engine Coolant System - Pressure Tester and pressure gauge 999 5230 PRESSURE METER 999 5230 Pressure Meter to pressure regulator.
- Pump up pressure.
- Check that line pressure rises by the same amount as the pressure in the regulator.
- 300 kpa + overpressure = line pressure.
- Disconnect hose from pressure tester.
Line pressure should return to 300 kPa.
OK - Checking residual pressure
Not OK - Replacing component
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Replacing component
Try a new pressure regulator.
Continue - Checking pressure regulator, pressure increase
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Checking pressure regulator, pressure increase
- Connect pressure tester 998 5496 ENGINE COOLANT SYSTEM - PRESSURE TESTER 998 5496 Engine Coolant System - Pressure Tester and pressure gauge 999 5230 PRESSURE METER 999 5230 Pressure Meter to pressure regulator.
- Pump up pressure.
- Check that line pressure rises by the same amount as the pressure in the regulator.
- 300 kpa + overpressure = line pressure.
- Disconnect hose from pressure tester.
Line pressure should return to 300 kPa.
OK - Stop fuel pump
Not OK - Fault-tracing information
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Checking residual pressure
- Ignition off.
- Disconnect cable between relay base terminals 1 and 3.
- Reinstall the fuel pump relay.
Line pressure must not drop below 200 kPa in less than 20 minutes.
OK - Disconnecting pressure gauge
Not OK - Replacing component
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Replacing component
- Incorrect residual pressure readings may be due to leakage from injectors, connections, pressure regulator, fuel pump non-return valve or lines. Repair as necessary.
Continue - Checking residual pressure
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Checking residual pressure
- Ignition off.
- Disconnect cable between relay base terminals 1 and 3.
- Reinstall the fuel pump relay.
Line pressure must not drop below 200 kPa in less than 20 minutes.
OK - Stop fuel pump
Not OK - Fault-tracing information
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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.
Continue - No Fault Found
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Stop fuel pump (FP)
- Switch off the ignition.
- Disconnect cable between relay base terminals 1 and 3.
- Reinstall the fuel pump relay.
Continue - Disconnecting pressure gauge
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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.
Continue - FAULT FOUND
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Fault-tracing information
Information
Fault-tracing information
The fault should be diagnosed and remedied. Since this is not the case the fault-tracing process has failed.
Complete the fault-tracing for those fault or try again.
Do you want to terminate fault-tracing at this time?
Yes - Exit fault-tracing
No - Attempt New Test
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Stop fuel pump (FP)
- Ignition off.
- Disconnect cable between relay base terminals 1 and 3.
- Reinstall the fuel pump relay.
Continue - Disconnecting pressure gauge
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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.
Continue - FAULT-TRACING FAILED
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Fault-tracing information
Information
Fault-tracing information
The previous test indicates that a repair must be made before continuing with fault-tracing. You cannot proceed with the fault-tracing tests at this point.
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Connect pressure gauge
- Supplement pressure gauge 999 5011 MANOMETER 999 5011 Manometer with nipple 998 9725 Adapter 998 9725 Adapter and adapter 999 5479 ADAPTER 999 5479 Adapter before use.
- Connect adapter to valve on fuel rail, with adapter in locked position (valve closed as in picture 1).
- Turn pressure gauge cock so it faces adapter 999 5479 ADAPTER 999 5479 Adapter.
- Connect other pressure gauge connector to fuel draining unit 981 2270 PUMP TROLLEY 981 2270 Pump Trolley , 981 2273 PUMP 981 2273 Pump and 981 2282 Tank 981 2282 Tank.
- Unlock adapter (illustration 2 valve open).
Continue - Starting Fuel Pump
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