onthecut wrote ...

In the course of wrestling with my glow plugs, inevitably had to move about many of the vacuum pipes running over the top of the engine. These are the ones that run across the top of the bulkhead side inlet manifiold to a control valve and feed the vacuum motors at the end of each inlet manifold.

Found after moving them that pretty much every internal plastic joining part was broken. Heat and age, I guess, but either way, absolute junk. I don't think this was just the result of me moving them on this occasion, so likely duff for a while.

Can't say I had noticed any difference in not having the inlet manifold flaps working, but if you are keen they should it may be worth checking these pipes along their length.

Mike.