1979-1993 & 94 Conv [Subscribe to Daily Digest] |
[Main C900 Bulletin Board | BBFAQ |
Prev by Date | Next by Date | Post Followup ]
Member Login / Signup - Members see fewer ads. - Latest Member Gallery Photos
Probably the Fuel Pressure Regulator Posted by RS [Email] (#15) [Profile/Gallery] (more from RS) on Thu, 22 May 2003 10:19:32 In Reply to: excessive black exhaust smoke, JohnVT, Thu, 22 May 2003 09:39:46 Members do not see ads below this line. - Help Keep This Site Online - Signup |
Most of the failure modes for the FPR involve excess gas going to the cylinders, either because it goes past the diaphragm into the vacuum system or because the spring gets weak.
A long shot would be the NTC sensor (with blue-green plastic head, screwed into the intake manifold flange between the intake runners for cylinders 2 & 3). With a sudden change like you say, I'd bet that it's probably the FPR.
If it happened during boost situations, I'd look at the boots and hose clamps between the turbo and the throttle body for cracks, splits, and looseness. They could let air escape under boost situations, tricking the ECU into feeding extra fuel for the amount of air that's actually getting to the engine. But, since you appear to be saying that it happens at idle, it's probably the FPR.
(On another matter and not to be over-critical, but 10k miles on a set of plugs is a bit high without regapping them. You may want to check them on general principles.)
posted by 63.148.1...
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.