The banner above is an advertisment - if it asks you to download software, please ignore.
Site News - 7/1: Members: Log In to See Fewer Ads! | 5/28: SAAB Evolutions/TSN T-Shirts $14
[General | Members | C900 | 9000 | NG900 & OG93 | 93 | 95 | NG95 | 99 | Sonett | Vintage Models | Clubs | Other Cars | FAQs | Gifts | Member Photo Galleries | Member Directory | Classifieds | Manuals | *Buddy Registry | *Mileage Registry | Polls | What's New | Raffle | Photo of the Month | Sponsors]

C900 Bulletin Board
1979-1993 & 94 Conv [Subscribe to Daily Digest]
(Search Author's Posts: e.g. Keyword:username)*Members Only

[Main C900 Bulletin Board | BBFAQ | Prev by Date | Next by Date | Post Followup ] Member Login / Signup - Members see fewer ads. - Latest Member Gallery Photos
Re: deleting cruise control on 87 SPG
Like This Post: - Subscribe to Daily Digest for this Bulletin Board
Posted by Bill S. [Email] (more from Bill S.) on Sun, 10 Oct 2004 02:31:20 Share Post by Email
In Reply to: deleting cruise control on 87 SPG, Saabu [Profile/Gallery] , Sat, 9 Oct 2004 18:59:03
Alert me when someone posts in this thread:
Members do not see ads below this line. - Help Keep This Site Online - Signup

I've noticed a lot of references lately to CC vacuum lines (and dump valves, etc) being sources of vacuum leaks (esp. on turbo cars), but I'm pretty sure that the vacuum system used for the CC is independent of the intake manifold vacuum lines. I think that the vacuum pump is the only source of vacuum for the CC system, and the CC vacuum system is not connected to the engine vacuum lines. I think people assume they're interconnected simply because they're both vacuum systems.

On turbocharged cars there is a vacuum switch in the CC system that _electrically_ connects to the APC system, but doesn't connect the vacuum systems. When vacuum is present in the CC system (CC operating) the switch opens, forcing the car to remain in base boost by defeating the APC solenoid (by interrupting power to the solenoid from the APC controller).

Also, in '86-on turbos the brake light switch is connected to the APC system, and on '89-on cars this switch is also connected to the CC system, but the two systems are not dependent on each other via this switch (they're each independently sensing brake operation), and certainly not by means of vacuum.

There are many problems that would arise if the two vacuum systems were connected. The dump valves would create a vacuum leak every time you stepped on the brake or clutch. Intake manifold vacuum would open the vacuum switch, defeating APC. When boosting, the turbocharger would pressurize the CC system. You could eliminate these problems with check valves, but you'd have to have one each direction, blocking flow in both directions, isolating the systems!

If you want to disable your CC system, installing the non-CC turn signal stalk will do it. The only other thing I would even consider doing would be to bypass the APC vacuum switch, but that would only be so that if the unused and static switch were to fail somehow it wouldn't relegate me to base boost. Other than that, I don't think you need to do anything.

posted by 24.18.226...
Posts in this Thread:
Alert me when someone posts in this thread:
Members do not see ads below this line. - Help Keep This Site Online - Signup
Post a Followup

No Site Registration is Required to Post - Site Membership is optional (Member Features List), but helps to keep the site online
for all Saabers. If the site helps you, please consider helping the site by becoming a member.

Name: Member Login / Signup - Members see fewer ads. - Latest Member Gallery Photos
E-Mail: (Optional)
Re-Enter E-Mail: (Confidential & Secure - Not revealed to other users!)
Note: Please check your spam folder for BB responses.

Subject:

Posting rules are simple - No for sale/wanted ads may be posted here - use the site classifieds.
You may not cross-post your message to multiple BBs.
Not permitted: political/religious topics and being disrespectful (personal attacks, insults, etc...).
 Site Members do not see any red text, inline ad links, bottom of page anchor ads, box ads, or anti-spam check.

Message: (please no for sale/wanted classifieds - post those in the Saabnet.com Classifieds)
Links are now automatically made active, no need for any special code (or use the Option Link field below) - don't put links in () or end with a '.'
To add inline images to your post, use [img]http://www.domain.com/img.jpg[endimg] (or use the Optional Image Link field below).

Links are now automatically made active, no need for any special code (or use the Option Link field below) - don't put links in () or end with a '.'
To add inline images to your post above, use [img]http://www.domain.com/img.jpg[endimg] (or use the Optional Image Link field below).
Optional Link: (e.g. http://www.saabnet.com/)
Link Title: (Optional)
Optional Photo/Image Link: (e.g. http://www.saabnet.com/img.jpg)
Photo/Image to Upload: (Please be patient while file uploads)



StateOfNine.com
SaabClub.com
Jak Stoll Performance
M Car Covers
Ad Available

The content on this site may not be republished without permission. Copyright © 1988-2024 - The Saab Network - saabnet.com.
For usage guidelines, see the Mission & Privacy Notice.
[Contact | Site Map | Saabnet.com on Facebook | Saabnet.com on Twitter | Shop Amazon via TSN | Site Donations]

Random Saabnet.com Member Gallery Photos (Click Image)
This is a moderated bulletin board - Posting is a privilege, not a right. Unsolicited commercial postings are not allowed (no spam). Please, no For Sale or Wanted postings, SERIOUSLY. Classifieds are to be listed in The Saab Network Classifieds pages. This is a problem solving forum for over 250,000 Saab owners, so expect to see problems discussed here even though our cars are generally very reliable. This is not an anything goes type of forum. Saabnet.com has been a moderated forum since 1988. For usage guidelines, see the Saabnet.com Mission and Purpose Page. Please remember that you are not anonymous. Site Contact | Site Donations | Other Sites by SP - Poverty2Prosperity.org | Run Club Menlo Park | ScreenBot


Site Members do not see red text instructions, bottom of the page anchor ads, or box ads.
Click here to see all the Site Membership Benefits!