vacum pipes again sorry :/

Hi All

I have recently screwed my after market bleed valve screw right in to see if i could get standard boost and the answer it no its running 1 bar still.

my problem is i would like to take all the vacum pipes off and re plum them all in as im not sure if all is ok.

I have got the vacum pipe layout printed off but cant get to grips with it.


I have 1 pipe from actuator to bleed valve (bleed valve has 3 nipples) to left nipple then the middle one is blanked off then the right one goes just on the back of the plenum.

Then i have another vacum pipe coming from rear of plenum to a 3 piece that then goes to sensor in the passenger wing and to a aftermarket boost gauge.

My question is how is this mesuring my boost if i only have a pipe from actuator to bleed valve then from there to rear of plenum ??? the boost sensor for the gauges isnt connected to it so what is it mesuring??

sorry if its hard to understand i hope some one can help me.

i could be paniking over nothing but like to make sure.

thanks
sam
 

PobodY

Moderators
Staff member
Eh?

The vacuum/boost runs off the entire manifold rather just the one port on your plenum; that's how you can measure it off a completely separate hose. - There should be three or four of them that come off the vacuum box on the back of the inlet manifold; one going to the vacuum assist on the brake master cylinder; two go to the carbon canister (a small one and a big one); then there's the line for the boost gauge(s), which I think is also connected to the BOV (at least it was on mine). - The sensor in your passenger wing is the boost sensor for your (standard) gauge.

If you're running a bleed valve, I'm pretty sure you don't want to block that middle port off or it's not actually bleeding anything. - Really that should be connected back up to the nipple on your inlet pipework (which is where the solenoid was originally connected), but nobody seems to bother with that. It would make sense that the air is bled back into the pipe before the turbo, and likewise any vacuum sucks filtered air rather than unfiltered through that bleed valve... I have a theory that this is one of the causes of a high idle because it's just letting unmetered air behind the throttle bodies.

Does that help, or have I misunderstood what you're trying to say or do?
 
Thanks pobody

I havent got the carbon canister.

i have just took most of it apart here is

on the back of plenum i have black box with 1 pipe of to brakes (on the top of black box) then on the side is 3 pipes.

starting from top :

1 goes to t juntion then of to fuel ramp thing ant straight on to another t juntion which goes to boost sensor and aftermarket gauge

2 goes to dump valve

3 goes to canister which has been blocked as i dont have canister.

then behind tps there is another vacum nipple i believe is for canister as well? if so i shall block as at the moment it goes to bleed valve.

and at the moment the intake maniford vacum has been blocked off .. do i switch them round? put the bleed valve to intake and block the one behind tps off??

thanks

sam
 

vss irvine

Well-Known Member
remove the bleedvalve and use a standard boost solenoid or a boost controller, bleed valves are evil......
 

bensmith907

New Member
remove the bleedvalve and use a standard boost solenoid or a boost controller, bleed valves are evil......
Ive heard that before somewhere? Time to swap mine soon I rekon then!

(Ha Ha. If Ive heard it twice it must be a fact!) Is that because its not very stable at controling Boost I.e +/-0.1BAR error
 
Last edited:

PobodY

Moderators
Staff member
It's because it doesn't do a good job and you'll get boost spikes and tail-off from it. - I'm sure stumo says they should only ever be used on Fords...
 

williams

New Member
Have you got the standard actuator? If you have a 1 bar actuator then you can't run less than 1 bar. I would bin the bleed valve. If you just want standard boost fit a standard boost solenoid, if you want to run more use an avcr, imo.
 
how can i reinstall the standard boost soloinoide? as i have found a diagram but i am missing the air duct bit on mine?



http://nissan4u.com/parts/sunny/er_...gine_electrical/vacuum_piping/illustration_1/

from actuator to t piece then up to intake manifold with the t going to boost solonoide. from boost solonoide to air duct i havent got that its been cut out.



can i just run it from actuator (with out t piece) to solonoide then from solonoide to intake manifold instead of air duct?

thanks

sam
 
i have just put pipe from actuator to tpiece to inlet manifold and boost solonoide and surprise i still have one bar of boost??
 

williams

New Member
Have you ever ran less than 1 bar on it? Connect actuator directly to inlat planem with no T pieces and see what it runs. It will be actuator pressure what it makes.
 
ok thanks i will try that tonight. No i bought the car running the way it is and just wanted to lower the boost back to standard and it wont do it, it just stays at one bar then when i tried reconnecting the standard boost solonoide it was lightly over 1 bar hence why i have put this post up.

thanks

sam
 

vss irvine

Well-Known Member
as said your going to have to check actuator pressure,

but you might have to invest in a boost controller.
 
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