Have been following this as my Pug206 has similar problems.
have today removed what I believe is the advance solonoid from the fuel pump.
Its on the later pump shown in Spider's photo which has a white cable tie around a black rubber cover, towards the bottom of the pump behind the throttle damper.
The solonoid when tested with a multi meter was showing closed circuit (no resistance), and when connected up and with the ignition switched on "ticked" for the duration of the glow plug light being on.
It has a small pin hole in the end and a similar hole halfway along its length above a fine wire mesh.
Looking at it it looked like the end should move out as if an electro plunger type affair, but when powered up it didnt.
Sorry didnt think to photgraph it whilst out.
Couldnt see anything else wrong with it, and couldnt see anything inside the pump( used a mirror to look) which maight look out of the ordinary.
On finding nothing jumping out as being wrong other than the suspected plunger bit not working, I replaced it, and switched on the ignition, didnt hear any ticking from the solonoid, started the car and took it for a run.
WOW must have disturbed something as it now runs like a good un, drives like a new car.
Am waiting for it to cool down to see how it goes when cold again.
I think we may be onto something chaps.
Pottsy, just so you know it only took a few minutes to remove and replace, so I think your earlier post as well as Spiders piccy may have saved the day.