Just an update guys, all sorted now, thanks to everyone who helped, anyway, sent the 2nd pump off to Dieselec for overhaul and all fitted and what a difference it has made. For £150 it was well worth it and i don't regret screwing this attempted unsiezing guide pin project.
One thing about my experience i would like to add with regards to a stuck guide pin, the lever that actuates the guide pin is quite a considerable thickness, it certainly isn't in my opinion something that would distort easily like some posts in other forum's suggested. This lever is a comfortable 2mm of thickness as well as the Guide Pin itself. Note to oneself 'Under no circumstances split the whole Diaphragm Housing from the pump body' because my experience was nothing but bad news. On saying that, if it is seized solid and no amount of WD40 or hitting works then spare yourself the grief and get your pump reconditioned.
If your guide pin is seized and you are unable to remove the diaphragm to free it, my advice to you is straight forward
1 mark current orientation of throttle lever on the throttle shaft. I cannot emphasise the importance of this procedure.
2 remove throttle lever, spring and spacers taking note of how they are fitted prior to removal.
3 With a 5mm Alan key unscrew brass plug behind where the throttle spring was and put in safe place.
4 Undo 4 screws on top of pump top cover and move to 1 side. Now mark/take note orientation of diaphragm in pump body, This should allow a few mm's of space to enable spraying.
5 get yourself a few cans of WD40 and fill the diaphragm housing with wd40, and be generous.
6 with the Alan key in hand put the long end into the recess where you removed the plug behind the throttle spring.
7 while pushing down on the diaphragm lightly tap the Alan key until the seized pin becomes free.
8 work the diaphragm up and down and the Guide pin as in 7 above, after a while the pin will be free enough to remove the diaphragm and further unsieze the guide pin.
If I had known then, what I know now, I would have saved myself a few quid, however, every cloud has a silver lining because now I have a new pump fitted and the turbo is finally working as it should, the Landy feels more like a monster rather than a sloth.
I am sure that Dieselec had tuned the pump while reconditioning it and the landy is better for it, it does chuck out a fair bit of smoke while stamping the foot down but hopefully that will be a deterrent for drivers following to close behind. I would definitely recommend Dieselec for Pump reconditioning as they've done a fantastic job for £150 and I'm so pleased with the results.
