10.8.1. Check and replacement of coils of ignition

Ignition coils two-output, type 3012.3705 or 406.3705.
The most frequent reason of failure of coils — the overheat or mezhvitkovy short circuit caused by operation of the engine with excessively big spark gaps of spark plugs or in the presence of gaps in connections of high-voltage wires.
Coils it is possible to check without removal them from the car.
It will be required to you: an autotester or an ohmmeter, a key "on 12".
1. For initial express check of the coil remove a tip from a spark plug, insert into it a serviceable candle, press the candle case to "weight" and launch the engine for a short time. Existence of a spark between electrodes of a candle indicates serviceability of the coil. Besides, coils can be checked the iskrosvechny diagnostic unit 1AP975000. For this purpose disconnect from the coil of a wire of high voltage and instead of them connect the diagnostic unit. Then turn a bent shaft of the engine a starter, in a rated sportsman of the diagnostic unit the spark in a step to operation of cylinders has to slip.

Prevention
It is forbidden to check the ignition coil, bringing a high-voltage wire to "weight". At such check the controller can fail.

2. For full check of the coil disconnect two blocks of wires from sockets of primary winding...
3.... and high-voltage wires from sockets of a secondary winding.
4. Connect an ohmmeter to conclusions of primary winding and measure its resistance, it has to be 0,4–0,5 Ohms.
5. Similarly connect an ohmmeter to conclusions of a secondary winding and measure its resistance, it has to be 5–7 kOhm.
6. If check revealed malfunction of the coil, turn out two bolts of fastening of the coil to a block head cover...
7.... remove bolts together with a clamping level and remove the coil.
8. Install the coil as it should be, the return to removal.