BMW 3 series E30

Since 1983-1994 of release

Repair and car operation

6.11. Check of pressure of fuel

THE GENERAL DATA

CARBURETTOR ENGINES

For check of pressure of fuel it is necessary to include a manometre between the fuel pump and a tube of giving of fuel in the carburettor. It is necessary also зашунтировать the return fuel valve included in a highway after the fuel pump.

PERFORMANCE ORDER

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

ИНЖЕКТОРНЫЕ ENGINES

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The prevention

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

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On cars with the pump of pumping pressure is measured at work of the basic pump and the pumping pump.

Check of work of the basic fuel pump and the pumping pump

PERFORMANCE ORDER

1. In system of injection L-Jetronic перемкните conclusions 30 and 87b on a socket of the relay of the fuel pump. 2. In system Motronic перемкните conclusions 30 and 87. 3. On models after 1987 for access to the relay and the management block turn away 4 bolts and uncover. 4. Then перемкните conclusions 30 and 87 on a relay socket.

At ignition inclusion from outside a tank the sound of the working pump should be listened. The given procedure concerns and the pumping pump.

Check of pressure of fuel

PERFORMANCE ORDER

1. Execute декомпрессию and disconnect the battery from weight. 2. In system of injection L-Jetronic and early systems Motronic disconnect a highway of giving of fuel on the fuel distributor. On late systems Motronic disconnect a highway on the fuel filter. 3. In highway rupture include a manometre. 4. Connect the battery to weight, перемкните conclusions to the pump relay, include ignition and consider pressure. 5. If pressure below norm check up presence of leaks in system, replace the filter and repeat measurements, check up the pressure developed by the pump and a condition of a regulator of pressure. 6. If pressure above norm check up a condition of a return gasoline pipe line. If the gasoline pipe line is not littered, replace a pressure regulator. 7. Check up pressure later 5 minutes after ignition deenergizing. If pressure below norm check up presence of leaks in system, check up the pressure developed by the pump, a condition of a regulator of pressure and atomizers.

Check of pressure of the fuel developed by the pump

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The prevention

For measurements the manometre joins directly the pump and standard procedure декомпрессии after tests is inapplicable. Therefore, the manometre with the pitting valve is required.

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PERFORMANCE ORDER

1. Execute декомпрессию and disconnect the battery from weight. 2. Disconnect a highway of giving of fuel on the distributor of fuel and attach to a highway a manometre. 3. Connect the battery to weight, перемкните conclusions to the pump relay, include ignition and consider pressure. 4. If pressure below norm check up presence of leaks in system. If the system is tight, replace the pump. 5. Check up pressure later 5 minutes after ignition deenergizing. If pressure below norm check up presence of leaks in system. If the system is tight, replace the pump. 6. Remove a crosspiece and dump pressure, having directed a fuel stream to a vessel.

Check of the pump of pumping of fuel

PERFORMANCE ORDER

1. Execute декомпрессию and disconnect the battery from weight. 2. Remove лючок the pumping pump (is under a back seat or under a rug in a luggage carrier, depending on model). Attach a manometre 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 below norm replace the pumping pump.

Check of the relay of the fuel pump

The 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. A rotation signal коленвала 3. Pressure of the battery 4. To the fuel pump (+)

5. The control of level of fuel 6. Weight 7. Pressure of the battery at ignition inclusion

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

1. Pressure of the battery 2. Pressure (+) from the main relay

3. Weight from the block of management Motronic 4. To the fuel pump (+)

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

PERFORMANCE ORDER

1. Include ignition and check up presence of pressure of the battery on conclusions 30 (engine M10) or 15 (М20 and М40) from an underside of a socket of the relay. The prevention If in cars with the battery in which it is mounted in a pressure luggage carrier on these conclusions is not present, check up a condition of a fusible crosspiece (on a current 50 And, located in 15 sm from the battery). 2. Switch off ignition, disconnect the relay from a socket, connect the voltmeter between conclusions 85 (-) and 86 (+) (engine M20) or between a conclusion 50 and weight (М10 and М40) and check up presence of pressure of the battery between these conclusions at starter inclusion. 3. In the absence of pressure check up safety locks and a chain. If pressure is, but the pump works only with a crosspiece the relay replace. 4. If the pump does not work and after relay replacement check up pressure on pump conclusions (see subsection 6.12). If necessary replace the pump.