Crown Victoria Poor Start High Fuel Consumption

I'm no expert, but those symptoms do sound fuel-related. Have you noticed any misfires, or had any work done recently? Just trying to get a better idea of what might be going on.

I haven't observed any distinct misfires beyond the uneven idling. No repair work has been done recently. Do you agree that the most plausible explanation is within the fuel injection?

Based on what you've described, a dirty or faulty injector is definitely a strong possibility. Given the age and mileage, it wouldn't be surprising. To be certain, you should probably have it checked out by a workshop. They can do proper diagnostics.

I consulted a technician, as you advised. The diagnosis confirmed a defective injection nozzle, likely due to accumulated deposits. The repair, including replacement, cost 515€. The car now operates optimally. Thanks for your help.