Jump to content
Ultimate Subaru Message Board

vacuum ?, please help


Recommended Posts

I was looking at the vacuum setup on my 87 turbowagon and saw that there are 3 lines coming out of the wastegate solenoid. The one in the back, to the wastegate, the one on bottom to the manifold, block, and the 3rd one in the front goes to the line running from the canister into the intake but has a tee on it. The section coming off the tee on the other side goes nowhere. It must have broke off something because the plastic nipple is snapped off in it. I search for past threads and it said that the line should go to the turbo outlet? I am very confused. Vacuum seems to unaffected because it idles with 17-18 inches. Goes right back after throttle. When i rev the motor to 2400 w/ clutch depressed i get no boost though. The book says i should get 6-7 psi. I am thoroughly confused. If anyone could help, i might be able to sleep tonite. thanks

Link to comment
Share on other sites

the turbo is only used under acceleration. In my RX The boost light only came on if I would floor it with the clutch depressed, and it would only flicker on for a second while the tach. was at about 5,000 and would go off at about 5,700-6,00 rpm. but once I would put it in gear and then get on it with a torque load on the motor the light would come on about 2,500 and wouldn't pump full boost till about 3,000 to 3,500. That was when you would feel it start to pull your head back to the head rest. Upon reaching cruising speed the turbo would fade out and not pump any more boost until I attempted to accelerate or if I started traveling up-hill and the motor had a higher torque load on it.

If it the turbo isn't isn't pumping any boost when you rev it to 2500 or so with the clutch depressed I wouldn't lose any sleep over it.

 

Will check my ride out tomorrow and see where the phantom vacuum line goes and post it for you. Enjoy the turbo while you have it. They are much fun.!.!

Link to comment
Share on other sites

Mitch, I am not the expert you are looking for but have several 87 turbo'd cars. and the FSM

(Factory Service Manual)

The FSM shows you have some lines incorrect.

The rear of the Waste Gate Duty Solenoid, is the input and should be connected to the small nipple on the output side of the turbo.

This provides the manifold pressure to the WGDS.

On the front of the WGDS are two nipples as you describe. One sits ninty (90) degrees to the solenoid and one is straight out.

The one at 90 degrees is the output and goes to the waste gate itself. The straight out nipple goes through a small resitrictor and to the Tee you mention.

This Tee and its lines connect to varrious other soleniods and is nothing more than a "breather" system. It connects to the MAF to turbo large dia. rubber pipe and provides clean air for the connected solenoids when they are in the vent mode.

Theory - at higher altitudes the ECU can vent, through the WGDS, some of the pressure which normally goes to the wastegate. This increases the boost pressure. Thus compensating for the power lost due to thinner air/02 content.

If you want a picture of said connections please email me.

P.S. It is very difficult to achieve enough exhaust flow at rest to make the turbo produce intake manifold pressure - please connect a pressure gauge and do this testing on the road.

Hope this helps

Link to comment
Share on other sites

I thought it was a little wierd that the book said that i should get boost under a no load situation. The hose i have right now that isn't connected to anything might be okay being left unconnected? The input to the wastegate solenoid still gets a direct signal from the manifold pressure so i'm wondering if it will work and if not, what goes where hose is coming from on the manifold. I am starting to become less confused, just more curious. ARGGGGGH!! Thanks for all the input though.

Link to comment
Share on other sites

Mitch, you have refered to "the book".

Which manual is this?

You now state

"The hose i have right now that isn't connected to anything might be okay being left unconnected?

You should connect this to the breather system as I noted.

Then

"The input to the wastegate solenoid still gets a direct signal from the manifold pressure so i'm wondering if it will work and if not, "

This question is a bit confusing, looking back to your original post

"The one in the back, to the wastegate"

This is the input to the Waste Gate Duty Solenoid.

It should not be connected to the waste gate, as I noted.

It should be connected to the intake manifold pressure via the small nipple on the turbo outlet housing.

You ask if I am not mistaken for the proper setup?

This line is also confusing to me

"what goes where hose is coming from on the manifold. "

I would take a picture of the "on the car system but it would be hard to see what goes where, so I "mocked up" this to show you where the lines run

Hope this helps

wastegatesetup1.jpg

Link to comment
Share on other sites

I was mixing up hoses. Sorry. Everything now goes where it is supposed to, but the breather hose, after it tee's with the line coming from the canister to the intake, goes to nowhere. This was the main question of the post. Where should it go after it tee's with the line going into the intake. You said it should go to the MAF, but where does it go after that? I just got all mixed up looking at it last nite. Once again, very sorry.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...