Hi Kevin and Welcome
What engine? 1.6 petrol?
Is the fault there always or only wet weather and could water be getting into the No. 1 spark plug well leaving brownish sputter marks on the nose of the coil?
Are you using a code reader and what faults are you getting. Are there messages on the dash?
Have you tried cleaning the crank sensor?
Was any work done on the intake manifold that could have left an air leak?
What colour is the No. 1 spark plug compared to the rest?
The next steps would be to swap the No. 1 injector with another and see if the misfire moves and then perhaps a compression test on the No. 1 cylinder.

 

Hi thanks for the reply I'm getting codes 0301 &0303 even when 100 miles still in tank.

 

Does it happen as much with a full tank and do you ever see an 0300?
Could the fuel pump be struggling to get the right pressure.
Renault No. 1 is at the gearbox end.
0301 and 0303 are misfires on both 1 and 3.

 

Sorry 0313 is the other code.

 

That 0313 fuel pressure code can be a bit ambiguous.
I could be blocked filter or failing pump but these might show up a loss of power.
It could even be the airflow sensor.
I would start with easy things like checking the wiring at the fuel pump, clean the plug anyway, run a bit of injector cleaner through the system.
I would still consider swapping that injector around to see if the fault could be made move. A dirty injector could be enough to cause uneven firing which the car could interpret as low fuel pressure.

 

Will do thanks