Pse check if anybody has such a (rare) installation. Mine suffered from intermittent idle problems and wouldn't start especially when warm without tricks. Pain to locate but finally it wouldn't start at all. Remove air valve, add WD40 and soak for some hours. Then take it to bits. the piston inside should move easily. Use an old connector and attach it to 12V DC (+ mark on connector) and the piston shoudl move with a clunking sound with ease. After that, everything back in and it runs fine!
No need to phone for a new one (tried but this is really a challenge).

Michael

BTW I had a BOSCH valve in my BX I think wich rotated instead of the in/out movement.

had this setup on my original 2.0SEi, would stick and cause the engine to die when slowing to a stop, or to rev when stationary. Not a lot of fun when you suddenly get 3K revs as your pulling up at a busy junction

I found a regular shot of carb cleaner down the feed air-hose, engine off, so it pools in the plunger area and then ignition on/off a few times would free it up, then start and it'd be fine for 4-6 months or so.

You used to be able to get a plunger kit for them....

rgds
Dave