03bf454c

6.4. The fuel pump/pressure of fuel - check

The fuel pump - check of Model with the carburetor engine
Attention! Be careful during the work with gasoline!
1. Check fuel tubes for leak existence.
2. If leaks are not revealed check the fuel pump, previously having disconnected a wire of the minus plug of the accumulator.
Check of an air vent

3.3 Check an air vent of the fuel pump (it is specified by an arrow) - if oil or gasoline follows from it, replace the fuel pump


3. Check whether fuel or oil follows from an air vent (3.3). If there is a leak, replace the fuel pump.
Check of operation of the pump
4. Disconnect a tube of supply of fuel from the carburetor and lower the end of a tube in suitable capacity.
Connect a wire of the minus plug of the accumulator. Disconnect wires from plugs of primary winding of the coil of ignition.
5. Turn a bent shaft of the engine a starter within about 10 seconds. If fuel is thrown out in the rhythmical portions, the pump means it is serviceable. If is not present, replace it.
Check of the inlet valve
6. Disconnect a hose of supply of fuel from the pump. Connect the vacuum manometer to a pump branch pipe. Turn the engine a starter.
7. The manometer has to register existence of constant depression. If pressure jumps, so the inlet valve does not provide sufficient sealing and the fuel pump it is necessary to replace.
Models with multipoint injection of fuel
8. Release pressure from a power supply system.

3.9 On models with multipoint injection of fuel use a special adapter (MD 998742 or similar) for installation of the sensor of pressure


9. Disconnect a tube of supply of fuel from a fuel collector and connect the sensor of pressure (3.9).
10. Start the engine and compare pressure shown by the sensor to pressure specified in the section of technical characteristics.
11. Disconnect a vacuum hose from the regulator of pressure and close the end of a hose. Take readings of the sensor of pressure.
12. Turn a bent shaft of the engine two or three of time. Start the engine and take readings of the sensor of pressure.
13. Slightly press a hose of the return pipeline of the regulator of pressure and check presence of pressure.
14. If in both tests pressure of fuel was low, so the fuel filter or a tube of supply of fuel is littered or the fuel pump is faulty.
15. If at the connected pressure regulator, pressure was high, so the regulator is faulty or on it depression does not arrive.
16. If at the connected regulator pressure was low, and after a regulator detachment - normal, so the regulator of pressure is faulty.
Models with point-to-point injection of fuel
17. Release pressure from a power supply system.

3.18 On models with point-to-point injection of fuel use a special adapter (MD 998742 or similar) for installation of the sensor of pressure


18. Disconnect a tube of supply of fuel from the block of throttles and connect the sensor of pressure (3.18).
19. Start the engine and compare pressure shown by the sensor to pressure specified in the section of technical characteristics.
20. If pressure low, check whether the fuel filter is littered, pressure regulator did not fail whether there is no leak in a tube of supply of fuel and whether the fuel pump is serviceable.
21. For performing more detailed diagnostics address experts.