Re: Mystery Hose/Cold Start Idle - Saab 900 Bulletin Board - Saabnet.com
NG900 & OG93 |
Vintage Models |
Clubs & SOC |
Other Cars |
Member Photo Galleries |
Member Directory |
*Buddy Registry |
*Mileage Registry |
What's New |
Photo of the Month |
Yes, a different part number - you can use 86/87/88... I'm sure you can find the actual part number or Bosch number by searching this site. But, it's almost assuredly the AMM. The issue on the '85 was far more subtle than that. The 1000rpm rev until warm is usually caused by a bad AMM. When the car is cold it relies 100% on the AMM for mixture. Once the O2 sensor warms up and starts providing feedback things tend to level out. When it's cold, and the AMM is providing bad data the idle is unstable as it leans out, starts to stall, and ECM opens the idle valve to keep it running, revs high, idle valve closes, gets lean, nearly stalls, and again and again. Sometimes you will find vacuum leaks, a bad O2 sensor, a bad NTC sensor, or on an '85 bad wiring, but the AMM is always the thing nobody changed for 30 years because the car generally runs right.
posted by 66.60.14...
Posts in this Thread:
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.
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 -
Your address is: 188.8.131.52 - Using CCBot/2.0 (https://commoncrawl.org/faq/) - Logged.
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!