I had a similar problem with a lucas filter unit (unscrew plunger type primer), found it coincided with low fuel levels and associated with negative pressure in fuel tank - air sucks in when removing fuel filler cap.
I found that the bleed vent was completely blocked from mud - situated in wheel arch by filler cap. It can be cleaned out but best replaced and tube unblocked too!
I have also had problems with a preheater block on a pug 205D with a bosch fuel filter. This is behind the engine and I had to replace the conections - my Peugeot spares man told what they sold most of!!!
Yeah, I had that too on my '93 205... Didn't remove the filler ass'y, tried to remove the blocking mud but it was too far away to be reached. I drilled a hole in the cap and it makes the trick. The only problem is the presence of greasy traces on the cap, due to fuel vapors, not a critical problem I'd say.
MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.