1979-1993 & 94 Conv [Subscribe to Daily Digest] |
![]() | [Main C900 Bulletin Board | BBFAQ |
Prev by Date | Post Followup ]
Member Login / Signup - Members see fewer ads. - Latest Member Gallery Photos
Re: huge vacuum leak??? Posted by RS [Email] ![]() ![]() ![]() In Reply to: Re: huge vacuum leak???, AMDG, Wed, 17 Mar 2004 12:11:21 Members do not see ads below this line. - Help Keep This Site Online - Signup |
Well, if you were losing *lots* of air from the induction system under boost, you'd get black smoke because the LH fuel injection system can't compensate for that much air loss using the O2 sensor.
At idle, the boost gauge should be down into the white because the intake manifold pressure is below atmospheric pressure.
Where does the hissing sound appear to come from? Under the dash? Somewhere in the engine compartment?
Take a look at the rubber bushings that hold the vacuum nipples into the intake manifold. If you can pull a vacuum nipple out easily, then the bushing isn't sealing right and may be a source of your leak. You may want to replace them on general principles, anyway.
If it appears to be coming from under the dash, then the sensing hose from the intake manifold may have split under the dash.
OR ... the check valve that serves the vacuum canister has bagged it and your heating control system gets pressurized when you go into boost. Do the heating doors change position when you go into boost?
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.
![]() |
![]() |
![]() |
![]() |
![]() |