1985-1998 [Subscribe to Daily Digest] |
![]() | [Main 9000 Bulletin Board | BBFAQ |
Prev by Date | Next by Date | Post Followup ]
Member Login / Signup - Members see fewer ads. - Latest Member Gallery Photos
Why ask why? Posted by Ari [Email] ![]() ![]() In Reply to: DI Died, ToddH, Wed, 17 Nov 2004 10:06:54 Members do not see ads below this line. - Help Keep This Site Online - Signup |
The DI died because it's a marginal design, living on top of a very hot object that shakes all the time. Heat, vibration, and high voltage - not a great recipe for long life.
Sounds like you got 145K miles out of it - that's a pretty great life for a DI. Many folks do everything right and get only 60K, or less.
Everything breaks - even rocks (see 'sand'). About the only thing you could do to prevent this would be to not drive the car.
What caused it? I'm sure it was a dielectric breakdown causing internal arcing and overcurrent, leading to one or more components being overstressed and burning out. That's just physics. In terms of what you could have done differently to prevent it, nothing. You've used the right plugs, gapped properly.
As to the irregular running now, it seems that at light throttle or idle, the engine runs poorly; under power it's better.
The first thing I'd do is pull the new DI and check the plugs. How do they look? Running rich or lean? Inspect the tops of the plugs - make sure you don't see burn marks. Use dielectric grease on the DI boots where they meet the plugs. Make sure those springs inthe DI boots are in place. Make sure the spark plugs have that funny screw-on cap, not just the threaded connection. The point here is that it sounds a little like poor ignition.
Otherwise, it sounds like lean running. This could be a weak fuel pressure regulator, or a vacuum leak. Yeah, I know you replaced a lot of stuff - go back and make sure it's all correct. At light throttle, a small vacuum leak makes a big difference. Under acceleration, the engine control adds lots of fuel, which will swamp out a small leak. But check those plugs - they live in the engine, and will tell you what's up.
posted by 192.249....
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.
![]() |
![]() |
![]() |
![]() |
![]() |