What is this?
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Member
Joined: Apr 2011
Posts: 128
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From: Adelaide
Car: '84 Trans Am
Engine: 305
Transmission: Auto
Re: What is this?
It has two pipes coming out of it. The top one goes to a small UFO shaped thing towards the back of the engine. The bottom one goes to nothing.
Joined: Sep 2005
Posts: 27,881
Likes: 2,434
Car: Yes
Engine: Usually
Transmission: Sometimes
Axle/Gears: Behind me somewhere
Re: What is this?
That is the EFE control valve.
EFE (Early Fuel Evaporation") is the valve in the right exh man outlet, that closes (by way of vacuum fed by the control valve) when the engine is cold. Helps warm up the intake manifold faster so that the motor comes out of "cold" behavior mode sooner after initial startup.
One vac line should go to a source of vacuum; one should go to the main valve.
There's a trhead on here about "vacuum diagrams"; find yours in that collection.
EFE (Early Fuel Evaporation") is the valve in the right exh man outlet, that closes (by way of vacuum fed by the control valve) when the engine is cold. Helps warm up the intake manifold faster so that the motor comes out of "cold" behavior mode sooner after initial startup.
One vac line should go to a source of vacuum; one should go to the main valve.
There's a trhead on here about "vacuum diagrams"; find yours in that collection.
Supreme Member
Joined: Feb 2008
Posts: 1,004
Likes: 1
Car: 90 IROC
Engine: 5.7 TPI
Transmission: 4L60
Axle/Gears: 3.23
Re: What is this?
I had one of those fail near the beginning of a 1000 mile trip in an old Impala I used to have. Car wouldn't climb hills, ran worse and worse like it just wasn't going to make it, yet it would continue to forge ahead. We stopped overnight midway and the next morning the car starts and runs fine. :? Until it got up on the highway and then started acting up again. Limped home and of course the car started fine the next day and the next and the next. It took me days and allot of tune-up parts before I finally unplugged the vacuum hose to the motor that operated the butterfly in the exhaust manifold. Smoothed right out, couldn't believe it. Took that stuff of and tossed it. I will never again risk having that system fail on me.
Joined: May 2004
Posts: 5,338
Likes: 72
From: Lexington, SC
Car: 1987 SC/1985 TA
Engine: 350/vortec/fitech
Transmission: T56
Axle/Gears: 3.27 9-bolt
Re: What is this?
EFE valve would be on the water neck (where the plug is now). That's the thermal switch for the EVAP system. It passes vapors from the EVAP canister to the carburetor under certain, vacuum and temperature conditions. The openings in the valve will be larger than vacuum lines, like the EFE uses. The EVAP canister should be located on the left, opposite the right battery tray.
