Approximately a week after having the crank shaft sensor replaced, my Renaul Clio decided that it wouldn’t start and showed exactly the same symptoms as before – turns over but no spark. Just so happened that it was dark and raining, I got a bit angry at this point and felt like Lando in Empire Strikes Back – “They told me they fixed it!”
Luckily (and surprisingly) the old 2nd-gear bump start down a hill worked and it started straight up as I simultaneously let the clutch out and turned the key (not sure if that was necessary but did it anyway for good measure). Hastily I made my way home.
Next day I called the garage and took the car in for them to check it with their diagnostic computer, no fault shown. The mechanic offered the explanation that it could be the battery, as when the starter motor is turned it drains quite a lot of power, and if the battery is old and tired then there might not be enough power to drive the ECU onboard computer. Sure enough, the battery was almost dead; it was not a lack of charge, but a lack of potential that had scuppered the ECU. This battery had been in the car since new and had done over 30,000 miles, not bad I suppose, definitely due a replacement.
I went to my local Wilco Motosave, they did a free battery check just to confirm that it was on it’s way out (it definitely was!) then had a powerful new battery fitted. £50 and job done.