Fiesta diesel injection nozzle issue

Sounds familiar. I had similar issues with my old Vauxhall Astra – rough idle, poor starting etc. Turned out one of the fuel injectors was faulty. Dirty injection valves can mess with the spray pattern, which leads to incomplete combustion. Have you checked for excessive black smoke? That's a sign of over-fuelling.

Thanks. Yes, there is black smoke. How did you fix the Astra's injector problem?

The Astra needed a new injector in the end. I'd suggest getting yours checked by a professional ASAP. Faulty injectors can cause damage elsewhere and increase emissions. It will only get worse as the clog hardens. Don't risk expensive catalyst repairs.

I consulted a mechanic, as you advised. It was a defective injection nozzle. Replacement and recalibration cost 515€. The car runs smoothly again.