BMW 3 Series E30

since 1983-1994 release

Repair and operation of the car

The air proofreader provides stabilization of turns of idling within ±200 rpm at variable loading of the engine idling. The proofreader represents the solenoidal valve opening a bypass for the air coming to zadrosselny space when falling turns it is lower than 750 rpm. When turns exceed 950 rpm the valve is closed and turns decrease.

The separate control unit of the proofreader of idling which is located under the forward panel of salon is provided in system of injection L-Jetronic. On the proofreader of idling there is an adjusting screw.

Are also provided in the early Motronic system the separate control unit of the proofreader of idling which is located under the forward panel of salon, and the adjusting screw.

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

Before check the engine has to be heated-up, onboard consumers are disconnected, sensors of turn of the gate and the sensor of oxygen have to be serviceable, leaks in the exhaust system and vacuum hoses have to be absent.

Connect a tachometer.

During the operation of the engine from the proofreader the buzzing sound has to be listened.

System of injection L-Jetronic

The control unit of the proofreader of idling (a look at the removed box for trifles)

At a detachment from the proofreader of the socket turns of idling have to increase up to 2000 rpm.

Check operation of the valve, having given on it tension from the battery. After removal of tension the valve has to open.

If results at least of one of tests unsatisfactory, then replace the proofreader's valve.

If results of tests satisfactory, then check the current consumed by the proofreader.

If current of the proofreader changes from 0,4 to 1,1 And, then it indicates that the engine cold, on malfunction of the sensor of temperature, on need of adjustment of idling, on leakage of vacuum connections or on the fact that onboard consumers are included.

As a rule malfunction of the block of idling is shown in the form of violation of contacts in the socket. Therefore, before acquisition of the new block check a condition of the socket. It is recommended to put temporarily the new block and to compare work of the proofreader with this block.

Motronic system

2 types of proofreaders – with 2 and 3 conclusions are provided in this system (the last are established on late models).

The screw for adjustment of the proofreader of idling in the plastic case

At a detachment from the proofreader of the socket turns of idling have to increase up to 2000 rpm.

Otherwise execute the following.

On the 2-wire proofreader check operation of the valve, having given on it tension from the battery. After removal of tension the valve has to open. Stop the engine and check the valve winding resistance which has to be 9–10 Ohms.

If results at least of one of tests unsatisfactory, then replace the proofreader's valve.

If results of tests satisfactory, then check the current consumed by the 2-wire proofreader or tension on the 3-wire proofreader.

On 2-wire the proofreader connect the ampermeter. Idling current has to be 0,4-0,5 A, if necessary adjust current.

If current of the proofreader changes from 0,4 to 1,1 And, then it indicates that the engine cold, on malfunction of the sensor of temperature, on leakage of vacuum connections or on the fact that onboard consumers are included.

If tension is not registered, then hand over the electronic block of idling (or the processor block of the engine on late models) in car service for check and repair.

Adjustment (only on early models)

Replacement