I firmly believe we're born with a sense of fair play – otherwise why would young kids say 'it's not fair' so often? It's a human instinct to play by the rules. This urge isn't shared by old Merc coupés. Having learnt last month that the Canems ECU is innocent of causing the persistent misfire (a verdict it shares with the plugs, leads, coil packs and sensors) I refitted the ignition system, determined to get to the bottom of the fault. The 500 SEC had other ideas.
Before I refitted the ECU I modified it by adding a heatsink
