Vaz 21213, Руководство по ремонту, Страница: 153 / 222

Engine gasps at all speeds
1. Ignition wires damaged, con-
nections loose or lead ends oxi-
dized
2. Electrodes worn or oily spark
plugs, strong fouling; cracks in
plug insulation
3. Carbon brush in ignition distrib-
utor worn or damaged
4. Strong burning of central con-
tact point on distributor rotor arm
5. Cracks, fouling or burnings of
rotor arm or distributor cap
6. Control module faulty - wrong
waveform of ignition coil primary
winding impulses
Engine lacking power or sluggish
1. Incorrect ignition timing
2. Jammed distributor weights,
weak weight springs in ignition dis-
tributor
3. Spark control module faulty -
wrong waveform of ignition coil pri-
mary winding pulses
WARNING. The vehicle is fitted with high energy transis-
torized ignition system with extended application of elec-
tronic components. Caution should be exercised to avoid
personal injury or damage to electronics. Always observe
the following rules.
Do not touch any ignition system parts (spark control
module, coil or HT leads) when the engine is running.
Do not start the engine through a spark plug gap and do
not check the ignition system through sparking between the
ends of the spark plug leads and earth lead.
Do not route LT and HT ignition leads together within one
wiring harness.
Always ensure the spark control unit is reliably earthed
through the retaining dowels, or its trouble-free operation
will be affected.
With ignition switched on, never disconnect the leads
from the battery posts and never remove the connector from
the spark control unit, since it may result in higher voltage to
some components and damaged control module.
Ignition timing - adjustment
Refer to Attachment 3 for the advance angle BTDC at crank-
shaft speeds of 750-800 rpm.
To check the ignition timing there provided three marks - 1, 2
and 3 (Fig.7-18) on the timing cover and mark 4 in the crankshaft
pulley, which corresponds to TDC of pistons No1 and No4 when
aligned with mark 1 on the timing cover.
The ignition timing is best checked and adjusted by means of
a stroboscopic timing light. Follow the procedure below:
- connect the timing light positive clamp to the battery positive
post, earth terminal clamp to the battery negative post, connect
the timing light terminal to No1 cylinder HT lead. Highlight in chalk
timing mark 4 on the crankshaft pulley;
151
1. Examine leads and connections.
Renew damaged leads
2. Examine plugs, regap spark
plugs, renew damaged spark plugs
3. Renew carbon brush
4. Clean central contact
5. Inspect, renew rotor or cap
6. Check spark control module with
oscilloscope, renew faulty control
module
1. Check and adjust ignition timing
2. Examine and renew damaged
parts
3. Check spark control module with
oscilloscope, renew faulty control
module
Fig.7 -17. Wiring diagram of ignition system:
1 - ignition switch; 2 - ignition solenoid; 3 - spark control unit; 4 - ignition coil; 5 - ignition distributor; 6 - spark plugs
Fig.7-18. Ignition timing marks:
1 - TDC mark; 2 - 5°advance timing mark; 3 - 10° advance timing mark; 4 - TDC
mark on crankshaft pulley