Peugeot Partner starting issues

I had similar symptoms with my Partner. Have you checked the state of your injectors? Dirty injectors can cause all the issues you described. It's worth checking the fuel pressure too.

Regarding the injectors, how did you inspect them? Did you use any specialized tools or cleaning agents? Also, where is the fuel pressure test port located on this engine?

I didn't inspect them myself. I took it to a workshop. They confirmed it was the injectors, cleaned them, and the issue was resolved.

Following your advice, I took my Partner to a trusted workshop. The diagnosis confirmed a defective injection nozzle, directly attributable to clogging. The repair, including replacement of the affected components and thorough cleaning, amounted to 515€. The vehicle now operates smoothly. Thanks for pointing me in the right direction!