Warning: Due to the high voltages produced by the electronic ignition system of Fiat Punto, extreme care must be taken when working on the system with the ignition switched on. Persons with surgically-implanted cardiac pacemaker devices should keep well clear of the ignition circuits, components and test equipment.
1 The spark plug (HT) leads should be checked whenever new spark plugs are fitted.
2 Remove the air cleaner assembly of Fiat Punto.
3 Pull the leads from the plugs by gripping the end fitting, not the lead, otherwise the lead connection may be fractured.
4 Check inside the end fitting for signs of corrosion, which will look like a white crusty powder. Push the end fitting back onto the spark plug, ensuring that it Is a tight fit on the plug. If not, remove the lead again and use pliers to carefully crimp the metal connector inside the end fitting until it fits securely on the end of the spark plug.
5 Using a clean rag. wipe the entire length of the lead to remove any built-up dirt and grease. Once the lead is clean, check for bums, cracks and other damage. Do not bend the lead excessively, nor pull the lead lengthways - the conductor inside might break.
6 Disconnect the other end of the lead from the ignition coil of Fiat Punto. Again, pull only on the end fitting. Check for corrosion and a tight fit in the same manner as the spark plug end. Refit the lead securely on completion.
7 Check the remaining leads one at a time, in the same way.
8 If new spark plug (HT) leads are required, purchase a set for your specific car and engine.
9 Refit the air cleaner assembly on completion of the checks.
10 Even with the ignition system of Fiat Punto in first-class condition, some engines may still occasionally experience poor starting attributable to damp ignition components. To disperse moisture, a water-dispersant aerosol should be liberally applied.