8V idling issues - SaabCentral Forums
Home Saab Pictures Saab Classifieds Saab Dealer Listings Saab Forum Saab Forum

Go Back   SaabCentral Forums > Saab C900, 1979-1993 & '94 Convertible (C=classic) > C900 Workshop

C900 Workshop Classic 900 (1979-1993 & '94 Convertible) Technical Forum.

SaabCentral.com is the premier Saab All Forum on the internet. Registered Users do not see the above ads.
Thread Tools Display Modes
Old 9th June 2005
dtom4 dtom4 is offline
Join Date: Jul 2003                                                
Location: CT
My Saabs: Newly Acquired 2001 9-5 93 900S
Posts: 259
Default 8V idling issues

Ever since I got the car 2 years ago it never seemed to idle correctly When first started in any weather it idles too low to the point where the idiot lights remain on. I would have to gently give it gas (too quickly it would stall) to get the lights out. Sometimes during normal driving it would idle at around 1100, sometimes around 600. If I lower idle with the air bleed bolt when its too high it would stall at other times because its too low. Raise it up and its too high at other times. Its gotten worse lately. On a cold start car will sputter and stall out when put in gear even when I raise the rpm's with the pedal and feather the gas. Usually takes a few times before I can get underway. I usually have to manually give it gas under any starting condition or the revs would be too low and during normal driving the idle fluctuates reandomly. Cars been fully tuned, all new parts, filters,timing, etc and I don't see any vauum leaks. I'm thinking maybe the cold start valve or o2 sensor. Both are originals. Any input would be appreciated.

Dave T
87 C900 8V, N/A A/T
only 62 K miles
Reply With Quote Quick reply to this message
Sponsored Links
Old 9th June 2005
MSOEMiller's Avatar
MSOEMiller MSOEMiller is offline
Saab Lunatic
Join Date: Feb 2002                                                
Location: Alhambra, CA
My Saabs: '87 900 8v N/A & '88 900 SPG, Both 5 spd
Posts: 1,222

The Bosch 02 sensor is pretty cheap for you approx. $30-40. The turbo 3 wire runs about $100. It does have a regular change schedule and you should change it even if it may not be the idling problem. It think the interval was every 50,000 miles (check on that).

This could be tough, since you say it's been tuned. I'd replace the vacuum lines. Silicone lines will run about $40-50.

Oh, I just saw the mileage. 62,000, WOW. That's less than my '87 had on it back when I got it in '99.
Reply With Quote Quick reply to this message
Old 9th June 2005
jetman jetman is offline
Saab on the Brain!
Join Date: Sep 2002                                                
Location: Guelph Canada
My Saabs: 1984 T8
Posts: 7,020

Before even getting into sensors or anything. Pull your throttle body and make sure that the butterfly is fully closing and moving freely. Also vaccum leaks can come from things like the dipstick/filler tube. Make sure as well that the your throttle and kick down cable aren't binding in any way.
Reply With Quote Quick reply to this message
Old 9th June 2005
REDTURBO84's Avatar
REDTURBO84 REDTURBO84 is offline
Saab Lunatic
Join Date: Aug 2002                                                
Location: no where
My Saabs: sold
Posts: 1,550

Hi , I'd start by wasteing a can of carb cleaner ,while its at idle ,around all the rubber hoses and gromets going to the intake and in it . If the idle picks up at a fitting its a vacuum leak.Also pinch the brake booster hose to see if it picks up. If not ,do a injector spray test. Pat
Advice is what we ask for when we already know the answer but wish we didn't.
Reply With Quote Quick reply to this message
Old 10th June 2005
Zelandeth's Avatar
Zelandeth Zelandeth is offline
Senior Member
Join Date: Jul 2003                                                
Location: Aberdeenshire, Scotland
My Saabs: 1989 C900i 8v 3dr Auto
Posts: 154

First thing I'd check: Aux Air Valve. Sounds like that could be sticking.

Also, check you've not got a leak between the throttle body and the air cleaner, as that would mess around with the air metering if there was a leak (however small) there.
Reply With Quote Quick reply to this message
Sponsored Links


Quick Reply

Register Now

In order to be able to post messages on the SaabCentral Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

Thread Tools
Display Modes

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

All times are GMT -4. The time now is 08:22 AM.

Powered by vBulletin® Copyright ©2000 - 2017, vBulletin Solutions, Inc.

top of page | sitemap | email us

copyright © 2003 - 2011 saabcentral.com, All rights reserved http://www.whiter.co.uk - valid xhtml - valid css
SaabCentral is an independently run website and is not affiliated in any way to Saab Automobile AB.

vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.

Garage Plus vBulletin Plugins by Drive Thru Online, Inc.