I know its what we are told to do but I finally bit the bullet and checked the vacuum hoses on my bus. Every one with a FI engined van should do this. My van runs pretty well but was lacking a bit of power compared to when I first had it, the pick up was poor and it felt like it was holding back and occasionally misfiring. Anyway, following a diagram I found on Ratwell I pulled all of the hoses, most were pretty brittle. cracked and crappy, I trimmed up the ends, a tiny little bit of grease to ensure a seal and pushed them all back together. Added a hose clip to those that didn't fell tight enough until I get around to buying new hose. The only hose I replaced was the distributor vacuum advance as I had a spare length. I'd been following the thread where the air filter box vacuum diaphragm thingy was broken, so left that disconnected just in case and put everything back together. I now have a transformed bus (well for me it is), tick over is still a bit rough but it's been like that since I imported it, but it picks up and runs really well, doesn't feel like it's holding back and no more misfire. Next thing to do is re connect the air filter box.... and check that each of the components in the vacuum system are still working.......or I may just leave it.
Did all mine this year. No more popping on over run which I think was a poor pipe from pressure reg to decal valve.
