Cause | Method of elimination |
The engine does not start | |
| Current does not flow through the breaker contacts: | |
| – the breaker contacts are dirty, oxidized or burnt; increased gap between contacts | – clean the contacts and adjust the gap between them |
| - loose fastening or oxidized wire tips in the low voltage circuit, break in the wires or short circuit | – check the wires and their connections; replace damaged wires |
| – the switch is faulty (contacts "30/1" and "15" do not close) or the ignition relay | - check, replace the faulty contact part of the ignition switch or ignition relay |
| – the capacitor is broken | - replace the capacitor |
| - break in the primary winding of the ignition coil | – replace the ignition coil |
| The breaker contacts do not open: | |
| – the gap adjustment between the breaker contacts is broken | – adjust the gap between the contacts |
| – the textolite block or bushing of the breaker lever is badly worn out | – replace the contact group |
| – the bearing of the breaker moving plate has failed | – replace the bearing or distributor |
| No high voltage supplied to spark plugs: | |
| - high voltage wire tips are loose in their sockets, have come off or are oxidized; the wires are heavily contaminated or their insulation is damaged | - check and restore connections, clean or replace wires |
| - wear or damage to the contact carbon, its sticking in the distributor cap | – check and, if necessary, replace the contact carbon |
| – current leakage through cracks or burnouts in the cover or rotor of the ignition distributor, through carbon deposits or moisture on the inner surface of the cover | - check, clean the cover from moisture and carbon deposits, replace the cover and rotor if they have cracks |
| – the resistor in the ignition distributor rotor has burned out | – replace the resistor |
| - the ignition coil is damaged | – replace the ignition coil |
| The spark plug electrodes are oily or the gap between them is not correct | Clean the spark plugs and adjust the gap between the electrodes |
| The spark plugs are damaged (crack in the insulator) | Replace the spark plugs with new ones |
| The order of connecting high-voltage wires to the terminals of the ignition distributor cap is violated | Connect the wires in the firing order 1-3-4-2 |
| Incorrect ignition timing | Check and adjust ignition timing |
| * The switch does not receive voltage pulses from the contactless sensor: | |
| - break in the wires between the ignition distributor sensor and the switch | – check the wires and their connections; replace damaged wires |
| - the contactless sensor is faulty | – check the sensor using an adapter connector and a voltmeter; replace faulty sensor |
| * No current pulses are sent to the primary winding of the ignition coil: | |
| - a break in the wires connecting the switch to the switch or to the ignition coil | – check the wires and their connections; replace damaged wires |
| - the switch is faulty | - check the switch with an oscilloscope; replace the faulty switch |
Engine runs rough or stalls at idle | |
| Too early ignition in engine cylinders | Check and adjust ignition timing |
| Large gap between spark plug electrodes | Check and adjust the gap between the electrodes |
| Small gap between breaker contacts | Adjust the gap between the contacts |
The engine runs unevenly and unstably at high crankshaft speeds | |
| The spring of the breaker moving contact is weakened | Replace the contact group |
| Large gap between breaker contacts | Adjust the gap between the contacts |
| The springs of the ignition timing regulator weights in the ignition distributor sensor have weakened | Replace the springs, check the operation of the centrifugal regulator on the stand |
Engine misfires in all modes | |
| The wires in the ignition system are damaged, the wire fastening is loose or their tips are oxidized | Check the wires and their connections |
| The breaker contacts are dirty, oxidized, burnt or displaced | Clean the contacts and adjust the gap between them |
| Wear of electrodes or oiling of spark plugs, significant carbon deposits; cracks in the spark plug insulator | Check the spark plugs, adjust the gap between the electrodes, replace damaged spark plugs |
| Worn or damaged contact carbon in the distributor cap | Replace the contact carbon |
| Severe burning of the central contact of the ignition distributor rotor | Clean the center contact |
| Cracks, contamination or burnouts in the rotor or distributor cap | Check, replace rotor or cover |
| Decreased capacity of the capacitor or a break in it | Replace the capacitor |
| Excessive distributor shaft runout; increased wear of the roller bushing | Replace the ignition distributor |
| * The commutator is faulty - the pulse shape on the primary winding of the ignition coil does not correspond to the norm | * Check the switch with an oscilloscope, replace the faulty switch |
The engine does not develop full power and does not have sufficient throttle response | |
| Incorrect ignition timing | Check and adjust ignition timing |
| Seizure of ignition timing regulator weights, weakening of weight springs | Check and replace damaged parts |
| Excessive wear of the breaker moving contact bushing | Check, replace the contact group |
| * The switch is faulty; the pulse shape on the primary winding of the ignition coil does not correspond to the norm | * Check the switch with an oscilloscope, replace the faulty switch |
* Malfunctions related to the contactless ignition system.
(Original source is on the resource: VazBook.ru)