4WD vacuum pipe question

[V8 Kannon]

Please can anyone help?
My newly purchased Hilux Surf was slow engaging and dis-engaging 4WD.
I read the advice here, but found out that there was very little vacuum, but when the T-piece was by passed and the vacuum pipe fitted straight to the solenoids, it works perfect every time.
The vacuum loss is where it fits onto the metal pipe on the "throttle" assembly. Can anyone tell me what the vacuum does the other side? Will it cause a problem with it disconnected?

[NiftyNev]

What T piece, what solenoid and what metal pipe on throttle assembly? You got me confused.

Nev

[V8 Kannon]

The pipe from the vacuum pump on the alternator goes into a T Piece, which connects to the solenoids inside the wing to activate the 4WD, then also joins onto a small metal pipe which is fixed to the turbo to throttle tube.
This small pipe then goes back onto the throttle body on top of the inlet manifold.

[davec170]

I may be reading this wrong, but:

If your vacuum tubing is connected to the turbo or inlet plenum it is plumbed up wrong! It would certainly explain why 4wd would be reluctant to engage.

[Hazzo]

there's vacuum pipework diagrams on here somewhere, best you tell what truck you have and you could be pointed in the direction. H

[BUSHWHACKER]

What T piece, what solenoid and what metal pipe on throttle assembly? You got me confused.

Nev

T piece = The plastic 'T' piece in the small diameter rubber vac pipes above the alt.
Solenoid = The VSVs on the inner wing.
Metal pipe on throttle assy. = The small dia metal pipe that runs alongside the silver intake ducting that has EFI DIESEL written on it.

[V8 Kannon]

Sorry, the vehicle is a 2.4 surf 1992.

[V8 Kannon]

I may be reading this wrong, but:

If your vacuum tubing is connected to the turbo or inlet plenum it is plumbed up wrong! It would certainly explain why 4wd would be reluctant to engage.

Hi Dave, the vacuum tube is not connected to the turbo or inlet plenum.
I have disconnected the T Piece as it was losing vacuum and just connected the pipe straight to the solenoids and it works perfect every time now.
I wanted to know what the vacuum was supposed to do on the other side of the T Piece.

[V8 Kannon]

T piece = The plastic 'T' piece in the small diameter rubber vac pipes above the alt.
Solenoid = The VSVs on the inner wing.
Metal pipe on throttle assy. = The small dia metal pipe that runs alongside the silver intake ducting that has EFI DIESEL written on it.

What does the small metal pipe do? It goes back to a rubber one, then a steel one and ends up in the area of the inlet manifold.

[V8 Kannon]

This is it, what does the RHS of the T Piece do please?
http://www.hiluxsurf.co.uk/attachmen...9&d=1198059789

[NiftyNev]

Right side goes to other VSVs for EGR operation and Small Butterfly operation on the throttle housing.

Nev

[V8 Kannon]

Thanks Nev, will it cause a problem if it's not connected?

[NiftyNev]

If you don't have vacuum to the throttle housing small butterfly then you will have rough engine shutdown. This is hard on the engine mounts.

Nev