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
Mis-typed - oil not fuel filler cap Posted by Ari [Email] (#2847) [Profile/Gallery] (more from Ari) on Wed, 23 Aug 2006 12:54:48 In Reply to: Re: Checks, Derek, Wed, 23 Aug 2006 11:31:51 Members do not see ads below this line. - Help Keep This Site Online - Signup |
I meant to say oil filler /dipstick cap. That leads directly to the crankcase, and can add air.
One failure mode of the FPR is for the internal diaphram to leak. The sign of that is if you pull the thin hose from the FPR to the intake off the intake and suck on it, you'll taste gas. The typical sign is a rich-running engine. First, fuel is leaking by the diaphram and into the intake, adding fuel. Second, the purpose of the FPR is to adjust fuel flow as a function of intake pressure (or vacuum). The idea is to keep the pressure drop across the injector constant. At high vacuum, there is a sucking effect in the intake, so it actually pulls fuel out - the FPR reduces fuel pressure to compensate. With a leaky diaphram, it doesn't reduce fuel pressure as much, so you run rich.
If the FPR is stuck at the lowest pressure, the pressure drop across the injectors would decrease as the engine speed (and intake pressure) increases, so you'd get less fuel and run leaner.
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.