 |
|
|
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
Re: '89 9000Turbo with engine miss problem Posted by Ari [Email]  (#2847) [Profile/Gallery]
(more from Ari) on Mon, 29 Oct 2001 15:31:33
In Reply to: '89 9000Turbo with engine miss problem, Bryan Kern, Mon, 29 Oct 2001 14:58:19 Members do not see ads below this line. - Help Keep This Site Online - Signup |
Actually, I believe it's a vacuum retard - it retards at high vacuum, and otherwise no retard. It's easy to check - remove the distributor cap, and suck HARD on the hose. If you see the plate behind the rotor turn a little, then it's working.
I doubt that it's timing, which is part of the vacuum advance. Timing would show up as ping/knock, and the APC would simply dial back boost. You wouldn't feel a miss.
The problem with missing at high boost is that it's harder to make a spark jump at high pressure than at low. As the boost pressure increases, any flaw in the spark delivery system shows up.
To echo the others - missing is usually an ignition problem. If you aren't using the exact specified NGK plugs, then get a set. Now is no time to be experimenting. Set the gap to what's listed on the decal in the engine compartment. Never assume a plug comes out of the box properly gapped.
I'm not sure how you go about checking spark plug wires. They might look fine, but have problems. I would replace them if they're over three years old. As the boost pressure increases, too high a resistance in one or more plug wires can cause a miss. As the boost increases, everything EXCEPT the plug looks like a good path for the spark. That can also be through the insulation of the wire to any convienent ground point. You'll never be able to measure that. Make sure the wires are held in the wire loom as they good through the valve cover - don't let them just lay around.
New plugs and wires, and it still misses - Don't forget the most important part of the spark system - the spark coil. Yes, they do fail over time, and that can show up as a failure in the internal insulation or a reduction in spark energy (due to internal shorts). I haven't had many spark coils fail over time, but it has happened, and it's very hard to find because nobody ever thinks to look there. So if all else fails, try swapping out the coil. I'd try a used one if you can to be cheap.
Good luck!
posted by 140.157....
, Mon, 29 Oct 2001 15:31:33 <-- Viewing This Message
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.
 |
 |
 |
 |
 |
