Cranking non-start
My daughter’s 2006 Renault Clio MKIII 1.4 16v petrol is refusing to start from cold, even after trying the spare key. We’ve never had any issues with it in a year-and-ahalf of ownership and 43,000 miles. It is serviced regularly.
Attempting to start first thing in morning from cold, the engine cranked over at healthy rate – the battery is only a few months old – and the rev counter appeared steady. After dozen or so attempts, we managed to get the engine to catch and kept the revs up as it went from rough to steady running. Keeping it at 2000rpm for a while, it idled OK until it was warm. The throttle body stepper motor is working and I could keep the revs up once running, so it responded to the accelerator pedal. It restarted instantly afterwards, and ran faultlessly during two test-drives.
It has never had any starting or drivability issues prior to this and the management light hasn’t come on. I checked the battery terminals, temperature sender, coils and crank angle connectors, but they were all very clean and with no evidence of corrosion. From the symptoms you describe, I would not expect this to be a fault of the key. If this was the case, it’s unlikely that the engine would attempt to fire, and it would not then catch in the manner you have described. I suspect that the engine had flooded for some reason and this would fit nicely with the symptoms you describe.
The cause of this may be due to the spark plugs or the crankshaft sensor. The 1.4 engine in the Clio MKIII does tend to suffer from this. If the sensor fails to send a signal on the first couple of cranks of the engine, it allows the plugs to become flooded. After this, starting will be difficult even though the plugs are sparking. If the condition of the spark plugs is not in doubt, I would replace the crankshaft sensor as a matter of course to prevent the problem recurring.