Where does diverter valve get vacuum?

Reply Subscribe

Thread Tools

Search this Thread

Apr 4, 2007 | 06:18 PM

Richard S

Thread Starter

Addict
Rennlist Member

Joined: Jun 2001

Posts: 3,720

Likes: 149

From: Elk Grove, Ca

Where does diverter valve get vacuum?

On the 1987 S-4, I was testing for vacuum at the diverter valve (controls the air from the smog pump), when the hose somehow came undone from the vacuum side. I have no idea where it connects to, and can't see anyplace that is obvious. When I pulled it off the diverter valve connection, there was vacuum present, so it must have been just barely connected at the vacuum side. Then it just came loose in my hand, and I can't for the life of me see where it was connected. I pulled off the air-box, all the other vac connections look fine. I looked in the workshop manual, but I could only find the early car vac diagrams. Any help is appreciated.

Rich.

Apr 4, 2007 | 06:19 PM

Rennlist Member

Joined: Dec 2001

Posts: 25,186

Likes: 105

I swear it comes from the "+" junction that comes from the throttle body area.

Apr 4, 2007 | 06:25 PM

Bill Ball

Under the Lift
Lifetime Rennlist
Member

Joined: Mar 2002

Posts: 18,648

Likes: 52

From: Buckeye, AZ

The source is the rear port of the two that on the top of the throttle in front of the MAF. If you remove the airbox and MAF, you can get a look at the source witha mirror and with small hands or a long forceps re-establish the connection. This connection faces forward and the routing of the line is forward even though the schematic shows otherwise. I did it lying on top of the motor. It was a pain.

Apr 4, 2007 | 06:26 PM

Richard S

Thread Starter

Addict
Rennlist Member

Joined: Jun 2001

Posts: 3,720

Likes: 149

From: Elk Grove, Ca

There is a 5-junction piece under the airbox, all the connections there are fine. I didn't see any "+" junction, where is it located, what's it hiding under, around, etc?

Apr 4, 2007 | 06:27 PM

Richard S

Thread Starter

Addict
Rennlist Member

Joined: Jun 2001

Posts: 3,720

Likes: 149

From: Elk Grove, Ca

Thanks Bill, I'll yank the MAF and have a look.

Rich

Apr 4, 2007 | 06:28 PM

Bill Ball

Under the Lift
Lifetime Rennlist
Member

Joined: Mar 2002

Posts: 18,648

Likes: 52

From: Buckeye, AZ

Rich, it does not go into the 5-way. It goes directly to the throttle body port. The 5-way goes to the other port on the throttle body top.

Apr 4, 2007 | 06:32 PM

Bill Ball

Under the Lift
Lifetime Rennlist
Member

Joined: Mar 2002

Posts: 18,648

Likes: 52

From: Buckeye, AZ

HOLD ON.... I might be thinking of the wrong valve. Give me a minute. I will post the diagram.

10 Best Non-Flat Six Porsches You Can Buy For Under $100K

Joe Kucinski

Porsche's Top 5 Most Questionable Naming Decisions

Verdad Gallardo

Pogea Racing's 964 Porsche 911 Reimagination Stands Out in a Crowded Field

Verdad Gallardo

6 Convertible Top MYTHS Most People Don't Understand!

Michael S. Palmer

2026 Porsche 911 Club Coupe is Spectacular, And Everything Wrong with the Porsche Market

Joe Kucinski

Talos Takes Your 991 Porsche 911 GT3 to the Next Level for a Cool $1.13 Million

Verdad Gallardo

9 Vehicles Porsche Helped Engineer that Aren't Porsches

Verdad Gallardo

9 Features and Characteristics That Only Porsche People Understand

Verdad Gallardo

I've Written 500 Rennlist Articles: Here's How Porsche Has Changed Along the Way

Joe Kucinski

10 Most Unnecessary Porsches Ever Built (And Why We Love Them)

Verdad Gallardo

Apr 4, 2007 | 06:47 PM

Richard S

Thread Starter

Addict
Rennlist Member

Joined: Jun 2001

Posts: 3,720

Likes: 149

From: Elk Grove, Ca

Bill, I looked at that diagram as well. I know the 5-way has nothing to do with it. In the diagram, the vac line coming off the throttle body just below the MAF goes to valve "F", which is listed as the charcoal canister valve. Does the line split off, and also run the diverter valve?

Rich

Apr 4, 2007 | 06:47 PM

#10

Rennlist Member

Joined: Dec 2001

Posts: 25,186

Likes: 105

I was thinking of the other line. As Bill's diagram shows, it is directly hooked to the rubber single on the TB

Apr 4, 2007 | 06:50 PM

#11

Rob Roy

On the Bandwagon
Rennlist Member

Joined: Feb 2004

Posts: 2,408

Likes: 3

From: Texas

Just an fyi - and I copied this idea from someone else - when I did an intake R&R I zip tied all the vacuum connections under the intake to ensure my paws wouldn't be accidentally pulling them off again

Apr 4, 2007 | 08:08 PM

#12

Richard S

Thread Starter

Addict
Rennlist Member

Joined: Jun 2001

Posts: 3,720

Likes: 149

From: Elk Grove, Ca

<<<this is me, I still can't find the f#@&ing connection. The one Bill referrenced isn't it.

Rich

Apr 4, 2007 | 08:11 PM

#13

Bill Ball

Under the Lift
Lifetime Rennlist
Member

Joined: Mar 2002

Posts: 18,648

Likes: 52

From: Buckeye, AZ

Quote:

Originally Posted by Richard S

If by diverter valve, you mean "I", the "blow-off valve", no, it goes to its own source on the BOTTOM of the throttle body. I can't imagine reattaching that without removing the intake manifold.

Last edited by Bill Ball; Apr 4, 2007 at 11:35 PM.