BMW 3 series E30

Since 1983-1994 of release

Repair and car operation

6.9. The air proof-reader of idling

THE GENERAL DATA

The air proof-reader provides stabilisation of turns of idling in limits ±200 rpm at variable loading of the engine idling. The proof-reader represents the solenoidal valve opening перепускной the channel for air, arriving in задроссельное space at falling of turns below 750 rpm. When turns exceed 950 rpm the valve is closed also turns decrease.

In system of injection L-Jetronic the separate block of management is provided by the proof-reader of idling who is located under the forward panel of salon. On the proof-reader of idling there is an adjusting screw.

In early system Motronic also are provided the separate block of management by the proof-reader of idling who is located under the forward panel of salon, and the adjusting screw.

In late system Motronic work of the proof-reader of idling the processor block operates, manual adjustment is not provided.

Before check the engine should be heated-up, onboard consumers are disconnected, turn gauges заслонки and the oxygen gauge should be serviceable, leaks in an exhaust system and vacuum hoses should be absent.

Connect a tachometre.

At engine work from outside the proof-reader the buzzing sound should be listened.

System of injection L-Jetronic

The block of management of the proof-reader of idling (a kind at the removed box for trifles)

On a socket there are numbers of conclusions.

At a detachment from the proof-reader of a socket idling turns should increase to 2000 rpm.

Otherwise stop the engine and check up resistance of a winding of the valve which should be 9–10 Ohm at 20 ° With.

Check up valve operation, having submitted on it pressure from the battery. After removal of pressure the valve should open.

If results at least one of tests unsatisfactory replace the valve of the proof-reader.

If results of tests satisfactory check up a current consumed by the proof-reader.

Open a socket and include the ampermeter between one of pairs respective () the conclusions, the second pair connect a crosspiece. Idling the current should be 0,4–0,5 And, if necessary adjust a current.

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The prevention

If the current of the proof-reader varies from 0,4 to 1,1 And it specifies that the engine cold, in malfunction of the gauge of temperature, on necessity of adjustment of idling, on негерметичность vacuum connections or that onboard consumers are included.

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If the current is not registered, hand over the electronic block of idling in car-care centre for check and repair.

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The prevention

As a rule malfunction of the block of idling is shown in the form of infringement of contacts in a socket. Therefore, before acquisition of the new block check up a socket condition. It is recommended to put temporarily the new block and to compare work of the proof-reader to this block.

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Adjustment

PERFORMANCE ORDER

1. Switch off ignition and connect a tachometre. 2. Be convinced that the ignition moment is exposed correctly (subsection 3.3.6.3 see). 3. Connect the ampermeter. 4. Check up a current which should be 0,45–0,47 And at 850–900 rpm on cars from a manual transmission and 0,46–0,48 And at 850–900 rpm on cars from an automatic transmission. 5. If necessary adjust a current, rotating the screw. The prevention On the proof-reader in the metal case the screw is taken out for case limits. If the case of the proof-reader plastic the screw is inside and for access to it it is necessary to remove the case from a back part of the proof-reader.

System Motronic

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The prevention

In this system 2 types of proof-readers – with 2 and 3 conclusions (the last are established on late models) are provided.

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The screw for adjustment of the proof-reader of idling in the metal case

The screw for adjustment of the proof-reader of idling in the plastic case

For access to the screw remove a hose.

At a detachment from the proof-reader of a socket idling turns should increase to 2000 rpm.

Otherwise execute the following.

On the 2-wire proof-reader check up valve operation, having submitted on it pressure from the battery. After removal of pressure the valve should open. Stop the engine and check up resistance of a winding of the valve which should be 9–10 Ohm.

On the 3-wire proof-reader stop the engine and check up resistance between extreme conclusions which should be 40 Ohm.

At connection 12 In to conclusions of the 2-wire proof-reader the piston (arrow) should move and close the air channel of the proof-reader.

If results at least one of tests unsatisfactory replace the valve of the proof-reader.

If results of tests satisfactory check up a current consumed by the 2-wire proof-reader or pressure on the 3-wire proof-reader.

On 2-wire the proof-reader connect the ampermeter. Idling the current should be 0,4–0,5 And, if necessary adjust a current.

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The prevention

If the current of the proof-reader varies from 0,4 to 1,1 And it specifies that the engine cold, in malfunction of the gauge of temperature, on негерметичность vacuum connections or that onboard consumers are included.

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If the current is not registered, hand over the electronic block of idling in car-care centre for check and repair.

Pressure on an average conclusion of a socket of the 3-wire proof-reader at ignition inclusion should be equal to pressure of the battery. Between extreme and average conclusions pressure should be about 10 Century

If pressure is not registered, hand over the electronic block of idling (or the processor block of the engine on late models) in car-care centre for check and repair.

Adjustment (only on early models)

PERFORMANCE ORDER

1. Switch off ignition and connect a tachometre. 2. Be convinced that the ignition moment is exposed correctly (subsection 3.3.6.3 see). 3. Connect the ampermeter. 4. Check up a current which should be 0,45–0,47 And at 700–750 rpm. 5. If necessary adjust a current, rotating the screw (rotation clockwise increases a current and on the contrary).

Replacement

PERFORMANCE ORDER

1. Disconnect a socket, remove an arm. Remove the proof-reader, having disconnected hoses. 2. Installation is carried out upside-down.