Checking engine systems (VW Golf 1)

1. Checking for spark at the ignition coil output

Remove the central high-tension wire from the distributor cap socket and hold it approximately 6 mm away from any metal part securely connected to the ground. Ask an assistant to turn the engine with the starter. If the coil is working properly, a strong bright blue spark should jump between the wire and the ground. Warning! This test cannot be performed on cars equipped with an electronic ignition system. To avoid electric shock, hold the wire with pliers with insulated handles or, as a last resort, through a thick dry rag.

2. Checking for spark on spark plugs

Disconnect the wire from one of the spark plugs. If you have a spare spark plug, attach the wire disconnected from the working spark plug to it and place the spark plug on an unpainted metal part of the engine. Have an assistant turn the engine over with the starter. A strong spark should appear between the electrodes of the spark plug.

NOTE: To avoid electric shock, hold the wire with insulated pliers or, as a last resort, by the insulated part of the cap through a thick dry cloth.

3. Checking the voltage at the ignition coil input

To check, you will need a test lamp with two wires with clamps. Connect the lamp between the positive (+) terminal of the ignition coil and the "ground". If the lamp lights when the ignition is on, then voltage is supplied to the coil. Disconnect the lamp wire from the positive terminal and connect it to the negative (-). If the lamp lights, then there is no break in the primary winding of the coil, and the coil should work.

4. Checking the distributor cap and high voltage wires

Remove the spark plug caps and then the distributor cap together with the high-voltage wires. Wipe the wires, caps and cap inside and out with a dry, clean cloth. In wet weather, it is recommended to treat the cap with a special water-repellent compound. Make sure that the cap, as well as the insulation and caps of the wires, are free of cracks, abrasions and other damage. Check the condition of the carbon brush in the center of the distributor cap and its spring. Inspect the internal contacts of the cap - they should not have excessive erosion.

5. Checking the contacts of the breaker and the distributor rotor

With the distributor cap removed, rotate the engine, observing the breaker contacts, which should move (close and open).

Remove the rotor and inspect it. The rotor contact should not show any heavy signs of erosion.

Inspect the contact surfaces of the interrupter. In case of strong burning, clean the contacts with a thin file. If the contacts are badly burned or blue from overheating, this may indicate a malfunction of the capacitor. By turning the motor so that the movable contact pad is at the highest point of the cam, adjust the gap between the contacts. Check if the movable contact or its wire is short-circuited to "ground". (Of course, all of the above applies to contact-type motors (not electronic) ignition system. On cars with electronic ignition, there are no breaker contacts)

6. Checking the fuel supply

Remove the fuel tank cap. If a vacuum is felt under the cap (when you open the cap, air rushes into the tank), then this means that the fuel tank ventilation hoses or plug valves are blocked (pinched), which may well be the reason for the engine stopping. Disconnect the fuel supply hose from the carburetor (or pressure regulator - on injection engines) and direct it into a wide container to avoid fuel spillage. Disconnect the wires from the ignition coil to prevent flashes in the cylinders, and check the fuel supply by turning the engine with the starter (on carburetor engines) or by turning on the ignition (on injection engines). If the fuel supply is satisfactory, reattach the fuel line and remove the air filter. Open the throttle valve and look down into the carburetor to check if fuel is getting into the carburetor diffusers and then into the intake manifold (they should be wet from fuel).

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7. Checking the battery connections and "ground" wires

Make sure the battery terminals are securely tightened and not damaged by corrosion. If any of the terminals have become very hot when the starter is running, you can be sure that there is a poor connection there. Make sure that the negative cable (ground cable) of the battery is securely connected to the body and that the connection point is not covered with corrosion products. If there is rust, clean the contact area to bare metal and tighten the connection securely. Similarly, check both ends of the engine ground cable.

8. Checking the electrical connections of the starter

Make sure all starter connections are clean and tight, including the thick wires that connect the solenoid to the starter motor and to the battery. When the starter is engaged, you should hear a distinctive click from the electromagnetic relay. Check for voltage by connecting a 12-volt test lamp between the thick wire that goes from the battery to the starter and the ground. The lamp should glow brightly. Connect the lamp between the two large (power) terminals of the electromagnetic relay. If the lamp does not glow brightly, this means that the starter is faulty (winding breakage, damage to the commutator or brushes). If the lamp is on, then when the starter is turned on (by turning the ignition key) it should go out. If the lamp does not go out when the starter is turned on, then the electromagnetic relay is faulty (solenoid or contacts).