986 Forum - The Community for Porsche Boxster & Cayman Owners - View Single Post - Purpose of evap valve under the intake manifold.

san rensho · 01-02-2014, 01:22 PM

I'm trying to chase down a vacuum leak in the evap system and I'm having trouble figuring out how the system works.

Near the carbon canister, there is a "tank vent valve" (also called a purge valve) that is controlled by the DME to purge the carbon canister of fuel vapor under certain conditions. The TVV works in conjunction with another valve near it, the "shut off valve" which opens and closes to let fresh air into the system when the TVV is open and purging the carbon canister.

So what is the purpose of another valve (I don't even know its name) under the intake manifold thats in the same circuit as the TVV?

01-02-2014, 01:22 PM	#1
san rensho Registered User Join Date: May 2011 Location: Miami florida Posts: 1,591	Purpose of evap valve under the intake manifold. I'm trying to chase down a vacuum leak in the evap system and I'm having trouble figuring out how the system works. Near the carbon canister, there is a "tank vent valve" (also called a purge valve) that is controlled by the DME to purge the carbon canister of fuel vapor under certain conditions. The TVV works in conjunction with another valve near it, the "shut off valve" which opens and closes to let fresh air into the system when the TVV is open and purging the carbon canister. So what is the purpose of another valve (I don't even know its name) under the intake manifold thats in the same circuit as the TVV? __________________ Current car 2000 Boxster 2.7l red/black Previous cars 1973 Opel Manta 1969(?) Fiat 850 Convertible 1979 Lancia Beta Coupe 1981 Alfa Romeo GTV 6 1985 Alfa Romeo Graduate 1985 Porsche 944 1989 Porsche 944 1981 Triumph TR7 1989 (?) Alfa Romeo Milano 1993 Saab 9000