Help With Vacuum Lines

[Drfatz]

I am installing all of the vacuum lines on my 1990 SE and have run into a small problem...I can't figure out where some of them go. My problem is I have a workshop manual for the later 4 cylinder and V8 cars which I guess came with an electric vacuum pump. I am not sure it that matters but it appears there are some different vacuum lines. For example there is a vacuum hose connection on the intake manifold which is facing the front of the engine towards the firewall...I can't figure out what this is for. Also, the top line coming out of the boost controller I can't figure that one out either. I have labeled the trouble lines in the below picture, keep in mind this is a diagram from a late model 4 cylinder I have a 90 SE. Any help would be most great full!

[DanR]

A connects to the outlet on the turbo

B goes through to the heater unit under the dash

C is from the electric vacuum pump in that small compartment in the boot (trunk) next to the expansion bottle.

[Drfatz]

No wonder I couldn't figure out where A connects, I installed an aftermarket turbo which does not have a fitting on the compressor side. As for C, my car has a mechanical vacuum pump so I guess that is where the line does?

A connects to the outlet on the turbo

B goes through to the heater unit under the dash

C is from the electric vacuum pump in that small compartment in the boot (trunk) next to the expansion bottle.

[Artie]

I think the S4 and on had electric vacuum pumps. The Non CC and CC cars had mechanical vacuum systems. I think you could just put a vacuum cap on it or plug that line off.

Artie

[Paula&Marcus]

Where did you connect A ????

For a proper boost control its essential that you connect A as close to the turbo outlet as possible.

Marcus

No wonder I couldn't figure out where A connects, I installed an aftermarket turbo which does not have a fitting on the compressor side. As for C, my car has a mechanical vacuum pump so I guess that is where the line does?

[Drfatz]

So far I have not connected A. I will have to install a fitting at the turbo outlet...not sure how I am going to go about this yet. I may do what Lotus did and just tap into the compressor housing and install it there.

Also, there is a vacuum vitting on the front of the intake manifold facing the firewall which is not shown in the above picture. I have searched through my S4s/V8 manual and it does not show it anywhere...anyone know what this connects to?

Edited June 20, 2007 by Drfatz

[Artie]

So far I have not connected A. I will have to install a fitting at the turbo outlet...not sure how I am going to go about this yet. I may do what Lotus did and just tap into the compressor housing and install it there.

Also, there is a vacuum vitting on the front of the intake manifold facing the firewall which is not shown in the above picture. I have searched through my S4s/V8 manual and it does not show it anywhere...anyone know what this connects to?

Graham,

This line connects into the ecm somewhere. I'll take a look today and see where it goes.

Artie

[Paula&Marcus]

NOOOOOOOOOOOO !

There is NO line connected to the ECU at all. The Esprit has 3 taps into the manifold (after the butterflies: MAP sensor, crank breather and charcoal canister) which are all the same (logic-wise).

The one facing the firewall is used for the charcoal canister.

I donot know where you got the diagram from, but its not complete, unfortunately. Please have a look at your rear-hatch-sticker or have a look in the workshop manual section EMH.2 page 13 and section EMH.4 page 2

There you will find the routing for all lines that are running around in the engine bay.

If you donot have a workshop manual, then its about time to get one. (you have a personal mail)

Cheers

Marcus

Graham,

This line connects into the ecm somewhere. I'll take a look today and see where it goes.

Artie

Graham,

I cannot believe that you have a turbo without a pressure line connector. Please have another look ... it has to be there. If its not there, the turbo manufacturer simply forgot to install it.

Cheers

Marcus

www.PUKesprit.de

So far I have not connected A. I will have to install a fitting at the turbo outlet...not sure how I am going to go about this yet. I may do what Lotus did and just tap into the compressor housing and install it there.

Also, there is a vacuum vitting on the front of the intake manifold facing the firewall which is not shown in the above picture. I have searched through my S4s/V8 manual and it does not show it anywhere...anyone know what this connects to?

[Artie]

NOOOOOOOOOOOO !

There is NO line connected to the ECU at all. The Esprit has 3 taps into the manifold (after the butterflies: MAP sensor, crank breather and charcoal canister) which are all the same (logic-wise).

The one facing the firewall is used for the charcoal canister.

I donot know where you got the diagram from, but its not complete, unfortunately. Please have a look at your rear-hatch-sticker or have a look in the workshop manual section EMH.2 page 13 and section EMH.4 page 2

There you will find the routing for all lines that are running around in the engine bay.

If you donot have a workshop manual, then its about time to get one. (you have a personal mail)

Cheers

Marcus

Graham,

I cannot believe that you have a turbo without a pressure line connector. Please have another look ... it has to be there. If its not there, the turbo manufacturer simply forgot to install it.

Cheers

Marcus

www.PUKesprit.de

Thanks Marcus, was going to add that the Line goes to the charcoal canister, after having a look.

Artie