Peugeot Expert diesel rough idle and poor starting

Your symptoms certainly suggest a fuel delivery issue. I had a similar experience with my older Renault Scenic, also a diesel. Rough idling, poor starting, the whole shebang. In my case, it turned out to be clogged injectors, not just one. Did you notice any black smoke or unusual engine noises accompanying these symptoms?

No black smoke that I've noticed, and the engine noise seems normal, just a bit rougher than usual at idle. So, if it was clogged injectors on your Renault, what did you do to fix it? Were you able to clean them, or did they need replacing?

Well, in my Scenic's case, I initially attempted to clean them using an additive in the fuel, hoping for a quick fix, like unclogging a drain with chemicals. Alas, it provided minimal improvement. Given the mileage and the severity of the symptoms, the mechanic advised replacement. He said cleaning them is often a temporary solution, if effective at all, especially with modern diesel injectors. Given your symptoms, I would suggest you seek a professional opinion from a workshop.

Thanks for the advice! It sounds like a trip to the workshop is in order. I appreciate you sharing your experience; I will get it checked out.