Site News - 6/4: Advertising Position/Commission Available | 5/10: Members: Log In to See Fewer Ads!
[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]

9000 Bulletin Board
1985-1998 [Subscribe to Daily Digest]
(Search Author's Posts: e.g. Keyword:username)*Members Only

[Main 9000 Bulletin Board | BBFAQ | Prev by Date | Next by Date | Post Followup ] Member Login / Signup - Members see fewer ads. - Latest Member Gallery Photos
Re: New to 9K.... need DI advice please
Like This Post: - Subscribe to Daily Digest for this Bulletin Board
Posted by Ari [Email] (#2847) [Profile/Gallery] (more from Ari) on Wed, 6 Aug 2008 17:05:53 Share Post by Email
In Reply to: New to 9K.... need DI advice please, lande, Wed, 6 Aug 2008 15:05:34
Alert me when someone posts in this thread:
Members do not see ads below this line. - Help Keep This Site Online - Signup

DIs can die a few different ways.
Bucking at high boost is usually a sign of too big a spark plug gap. So yes, check that gap, and make sure it is on the tight side of spec (I go for about 0.9mm). And yes, make sure you are using the exact NGKs specified in the manual. No substitutions!
The trouble is, the spark gap isn't just on the plug. Inside the DI are four coils. The top of the coil is metal, and it connects to the spark plug through a spring in the rubber boot. Any gap between the top of the coil and the spring, and the top of the spark plug and the other side of the spring is still spark gap, and it counts. Not as much as the plug where the pressure is higher (and the spark has to work harder to jump).
As a first step, pull off the DI and flip it over. Undo the Torx screws holding the bottom to the metal plate. Pull it off. You'll see the four coils. Do you see any signs of arcing on the metal top of the coils? If so, pull out the spring and lengthen it a little. Hold the DI up to a bright light. You should see fluid inside each coil. They should be about 90% full. If one is low, replace the DI. If you see oil on the coils, or signs of burning, replace the DI. Look at the top of the spark plugs - see any signs of arcing? If so, another weak spring.

I have seen a DI issue where the car had a subtle miss at low RPM that cleaned up at higher RPM.

It almost sounds from your description that the car has a serious miss at lower RPM ("I have a seriously bad miss from idle to regular driving speeds") that cleans up at high RPM/boost ("When I stomp on it and engage the turbo it does fine"). That sounds like a lean mixture issue. How did the old spark plugs look? Worn, yes, but what color? Did they look whitish, the sign of lean running? How about the new ones? Under boost ,the engine control adds a lot of fuel and the boost can overcome vacuum leaks.

If the plugs look lean, do a check for vacuum leaks. Make sure the hose to the charcoal canister is in place. To check the canister, pop off the right front turn signal assembly and look in. Look for blown hoses in other places, too. Cracks, or a small vacuum hose that just fell off a nipple.

posted by 76.243.12...
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 © 1988-2025 - 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!