Table of contents: High voltage wire ↓ Ignition sequence ↓
The high voltage unit of the ignition system, in addition to the ignition coil and distributor, includes the high voltage wire, the anti-interference connector and, of course, the spark plugs.
High voltage wire
Typically thick high tension wires from the ignition coil to the spark plugs (or to the distributor) do not cause problems.
They must be firmly inserted with their anti-interference connectors (against radio interference) into the sockets of the distributor cap or ignition coils. Their plug connectors must not be oxidized, and they must have reliable contact with the spark plug connectors.
If the high tension wire has become hard and brittle, you must install a new wire. They are sold for all engines assembled with the appropriate connectors.
You cannot use just any spark plug connectors in an Audi. The connectors must have an internal resistance that matches the ignition system.
Tips: "Leaky" sections on the high-voltage wire are easy to spot if you look into the engine compartment at night while the engine is running. Then you can clearly see the spark jumping on the wire. On the contrary, weak flashes of light "running" along the wire do not cause concern.
If the engine is constantly or occasionally (in damp weather) if not all cylinders are working, the reason is sometimes in defective spark plug connectors. There, sparks break through the insulating material between the metal shell and the high-voltage electrode. Most often, it is not visible from the spark plug connector whether it breaks through or not. To check, replace the spark plug connector with another one. Temporary help on the road: remove the metal screen of the connector.
Ignition sequence
For balanced engine operation, the fuel-air mixture is ignited in the cylinders not in a row 1-2-3-4 (-5-6), but alternately. In accordance with this ignition sequence, the ignition wires are inserted into the distributor cap of the 1.6 liter engine. If the distributor pin, with the distributor cap and dust cover removed, points to the risk on the edge of the housing, then the ignition moment falls on the 1st cylinder (the very first in the direction of travel).
Our engines have the following ignition sequence:
Four-cylinder engine: 1-3-4-2. The distributor finger in the 1.6L engine rotates to the right (clockwise). In the 1.8 l 92 kW engine, the ignition coil of the 3rd cylinder also supplies power to the 2nd cylinder via a high-voltage wire. The ignition coil of the 4th cylinder also supplies power to the 1st cylinder via a high-voltage wire. In the 1.8 l 110 kW engine, there is no risk of confusion due to separate ignition coils.
Six-cylinder engine: 1-4-3-6-2-5. No ignition distributor – the location of the high-voltage wire connections on the ignition coil pack corresponds to the location of the cylinders. Example: the high-voltage wire in the rear right connection point goes to the rear right cylinder.
[Content source: the specified website AudiManual]