E30 series BMW 3

since 1983-1994 of release

Repair and car operation



E30 BMW
+ 1. Maintenance instruction
+ 2. Maintenance
+ 3. Engine
+ 4. Cooling system
+ 5. Heating and ventilation
- 6. Fuel system
   6.2. Specifications
   6.3. Check of system of injection
   6.4. Measuring instrument of a stream of air
   6.5. Throttle branch pipe
   6.6. Regulator of pressure of fuel
   6.7. Nozzle of start-up of the cold engine and thermotimer
   6.8. Check and replacement of nozzles
   6.9. Air proof-reader of idling
   6.10. Order of a decompression of fuel system
   6.11. Check of pressure of fuel
   6.12. The fuel pump, the pump of pumping and the fuel level sensor in a tank
   6.13. Gasoline pipe lines and union
   6.14. Fuel tank
   6.15. Air filter
   6.16. Cable of a drive of a butterfly valve
   6.17. Carburetor
+ 7. Exhaust system
+ 8. Transmissions
+ 9. Coupling
+ 10. Brake system
+ 11. Running gear
+ 12. Body
+ 13. Electric equipment
+ 14. Good advice



6.11. Check of pressure of fuel

GENERAL INFORMATION

CARBURETTOR ENGINES

For check of pressure of fuel it is necessary to include a manometer between the fuel pump and a tube of supply of fuel in the carburetor. It is necessary also зашунтировать the return fuel valve which has been switched on in the highway after the fuel pump.

PERFORMANCE ORDER
In the absence of a manometer pressure can be checked on a stream from the hose disconnected from the pump, turning the engine a starter (disconnect also high-voltage wire from the ignition coil).

INJECTOR ENGINES


Prevention

The fuel filter should be in a satisfactory condition. If the filter is littered, it is necessary to replace it.


On cars with the pumping pump pressure is measured at operation of the main pump and the pumping pump.

Check of operation of the main fuel pump and pumping pump

PERFORMANCE ORDER
1. In system of injection of L-Jetronic перемкните conclusions 30 and 87b on the socket of the relay of the fuel pump.
2. In Motronic system перемкните conclusions 30 and 87.
3. On models after 1987 for access to the relay and the control unit unscrew 4 bolts and uncover.
4. Then перемкните conclusions 30 and 87 on the relay socket.

At ignition inclusion from a tank the sound of the working pump should be listened. This procedure belongs and to the pumping pump.

Check of pressure of fuel

PERFORMANCE ORDER
1. Execute a decompression and disconnect the battery from weight.
2. In system of injection of L-Jetronic and early systems Motronic disconnect the highway of supply of fuel on the fuel distributor. On late systems Motronic disconnect the highway on the fuel filter.
3. In a rupture of the highway include a manometer.
4. Connect the battery to weight, перемкните conclusions to the pump relay, include ignition and consider pressure.
5. If pressure is lower than norm, check existence of leaks in system, replace the filter and repeat measurements, check the pressure developed by the pump and a condition of a regulator of pressure.
6. If pressure is higher than norm, check a condition of a return gasoline pipe line. If the gasoline pipe line is not littered, replace a pressure regulator.
7. Check pressure 5 minutes later after ignition switching off. If pressure is lower than norm, check existence of leaks in system, check the pressure developed by the pump, a condition of a regulator of pressure and nozzles.

Check of pressure of the fuel developed by the pump


Prevention

For measurements the manometer joins directly the pump and standard procedure of a decompression after tests is inapplicable. Therefore, the manometer with the pitting valve is required.


PERFORMANCE ORDER
1. Execute a decompression and disconnect the battery from weight.
2. Disconnect the highway of supply of fuel on the distributor of fuel and attach to the highway a manometer.
3. Connect the battery to weight, перемкните conclusions to the pump relay, include ignition and consider pressure.
4. If pressure is lower than norm, check existence of leaks in system. If the system is tight, replace the pump.
5. Check pressure 5 minutes later after ignition switching off. If pressure is lower than norm, check existence of leaks in system. If the system is tight, replace the pump.
6. Remove a crossing point and dump pressure, having sent a fuel stream to a vessel.

Check of the pump of pumping of fuel

PERFORMANCE ORDER
1. Execute a decompression and disconnect the battery from weight.
2. Remove the hatch of the pump of pumping (is under a back seat or under a rug in a luggage carrier, depending on model). Attach a manometer to the final union of the pump.
3. Connect the battery to weight, перемкните conclusions to the pump relay, include ignition and consider pressure. If pressure is lower than norm, replace the pumping pump.

Check of the relay of the fuel pump

Scheme of the device of the relay of the fuel pump and designation of conclusions (the 4-cylinder engine)

1. A signal from a starter
2. Signal of rotation of the crankshaft
3. Tension of the battery
4. To the fuel pump (+)
5. Control of level of fuel
6. Weight
7. Tension of the battery at ignition inclusion

Scheme of the device of the relay of the fuel pump and designation of conclusions (the 6-cylinder engine)

1. Tension of the battery
2. Tension (+) from the main relay
3. Weight from the Motronic control unit
4. To the fuel pump (+)

The relay of the fuel pump on the 4-cylinder engine (And) and on the 6-cylinder engine (In)


PERFORMANCE ORDER
1. Include ignition and check existence of tension of the battery on conclusions 30 (M10 engine) or 15 (М20 and М40) from a reverse side of the socket of the relay.
Prevention

If in cars with the battery in which it is mounted in a tension luggage carrier on these conclusions is not present, check a condition of a fusible crossing point (on a current 50 And, located in 15 cm from the battery).


2. Switch off ignition, disconnect the relay from the socket, connect the voltmeter between conclusions 85 (-) and 86 (+) (M20 engine) or between a conclusion 50 and weight (М10 and М40) and check existence of tension of the battery between these conclusions at starter inclusion.
3. In the absence of tension check safety locks and a chain. If tension is, but the pump works only with a crossing point, the relay replace.
4. If the pump does not work and after relay replacement, check tension on pump conclusions (see subsection 6.12). If necessary replace the pump.