dump valve fitting / boost problem
 

i've just fitted a dump valve to my ca18et S12. the valve isnt dumping & my standard boost gauge is staying around zero. i have plumed the vacume hose to the blanked niple next to the clutch master cylinder as discussed on a previous threat

the forge dump valve was off a s14. is it not dumping or reading boost beacuse the spring is too hard for my puney 7psi or have i connected the vacume incorrectly?

any help would be a great help :)

Have you got a picture of the way it's connected?

giz 5min & i will have :)

actually scratch that, my dad's F'd off with the camera GRRRRRR! i'll have to wait until tomorrow

:furious

is the car actually making boost?

i dont think so, its hard to tell with such low boost as standard? possibly not. i'm goin to have a good look over it in the morning... could a dodgy vacume prevent the turbo from working?

the tansparant hose is my vacume, is this to the correct place?

http://img715.imageshack.us/img715/4417/imgp0407.jpg

yeah thats fine. Unplug it and just check its sucking at idle. there could be a block

i've just had all of the boost pipes off & found that the hose on the actuator was split, i've replaced it & reinstalled all the boost pipes but the boost gauge & dump valve are still not working???

does any1 know if the problem is because this dump valve is off an s14, is the spring too hard for 7psi to move?

**update**

i've changed the spring in the dump valve for a lower psi one (donation from a mate) but still no PSSSSSSSHHHHH!

after further examination, the vacume is in the correct place & sucking good, boost pipe are tight & secure, actuator hose replaced & secure, but boost gauge is not budging?

i've noticed the arm on the actuator is not moving when revving?

take the r clip out , the actuator arm off and see if you can open the wastegate, it could be seized matey.

done what you said & the wasgate seems to move ok, only about 10mm tho. when revving the engine with the actuator arm disconnected from the wastegate is doesnt move, does this mean the actuator is broken?

take the pipe from the air filter to the turbo off and check the turbo blades are spinning freely. Ive seen a few silvias with siezed turbo blades in the past.
If its not that you possibly have a boost leak somewhere that is allowing the boost to release from it rather than via the dump valve.

check as pukka says, but also where have you plumbed in the dump valve (pressure side) and do you still have the std crossover pipe, the big orange seal on the lower side often leaks.

can you take a pic from further back so we can see a bit more of the engine bay.

problem solved! some clown has sold me a nackerd dump valve, i know this is one of the 1st things to check but i had "dump valve denial"

thanks for the help peeps, am sure these tips will be handy to know in the future