lucas boost compensator problem

[parrotveasey81]

i seam to have a problem with my lucas boost compensator,as in it dont work
for the last few days sometimes it has alot of power and hits full boost(20psi) easy and then it has next to no power and is hard to hit full boost

so i done a quick test today to see if the boost compensator was working or not,so i pulled the boost pipe off and blocked it up then done a quick(well far from quick) 30-80 from 3rd gear
http://www.youtube.com/watch?v=N58zY_a-D9Y
well after that i now know that some times my boost compensator is not always working

so is there any common problems with them???
maybe like the pin stick's some time's???

any help is much appreciated

[Kwik]

internally torn so not always holding boost?

But is a perfect excuse to either

1)depending on age swap for a later lucas system as they run at 150bar as opposed to 130bar for the earlier

2)Bosch it as that runs at 175bar

the later lucas may well be easier to find then a bosch but obvs won't have the benefits of a bosch'd system

[parrotveasey81]

i will bosch it but not antill the engine is fitted in a swb vitara

torn??do you mean the diaphragm

i do have a spare engine and pump in the garden but dont realy want to swop the pumps over

[Kwik]

Yea that's what I mean the diaphragm could be sealing it self with oil from breathers.

May be worthwhile swapping the compensator only

[parrotveasey81]

well i swoped the boost compensators over today and still nothing so i made up a test rig so i could feed it some boost on tickover to see if it was a boost leak but that made no difference so unless it needs to be part/open throttle to work i think my pump is on its way put or at the very least getting blocked up inside