Granada Mk3 Scorpio Mk1 2.0 DOHC 89 > 91. Granada Mk3 Scorpio Mk1 2.0 inj DOHC 89 > 95. They have a waterproof seal around the spark plug and are resistant to oil, water and under-bonnet corrosive materials.Ignition leads connect the distributor to the spark plugs and therefore form an important part of the overall car engine ignition system.