What are these things?
Thread Starter
Instructor
Joined: Nov 2001
Posts: 248
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From: Houma LA
What are these things?
I was going over my engine yesterday and noticed two plug type things. Both appeared to be broken and/or missing pieces. I took a couple pics. Please help me out here. Thanks
--J.thib
--J.thib
Burning Brakes
Joined: Jul 2000
Posts: 1,118
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Re: What are these things? (ice pac)
In your picture, the missing fittings are temp controlled switches. The one on the right is for the EFE, as Twinnie said. It has twin vacuum ports, one going directly to the exhaust manifold EFE and the other has a T fitting to the carb and the air diverter valve of your air pump control assembly (all that stuff is missing from the your car). The other missing switch is the ECS (evaporative control system). It also has two ports, one going to the base of the carb (below your throttle position sensor) and the other goes to the fuel vapor canister. To the right of the missing fittings you'll see another fitting with a yellow & black wire. That's the temp sensor that's used by the computer.
[Modified by Chris81, 7:15 PM 10/5/2002]
[Modified by Chris81, 7:15 PM 10/5/2002]
Team Owner
Joined: Aug 1999
Posts: 30,995
Likes: 99
From: Ontario
Re: What are these things? (ice pac)
Yours are long gone but one is the EFE TVS valve and the other is the EGR TVS valve. EFE is the early fuel evaporative system and EGR is the exhaust gas recirculation system. Both are thermal vacuum (TVS) actuated.
http://temp.corvetteforum.net/c3/pau...ssions_001.jpg
[Modified by paul79, 7:30 PM 10/5/2002]
http://temp.corvetteforum.net/c3/pau...ssions_001.jpg
[Modified by paul79, 7:30 PM 10/5/2002]
Melting Slicks
Joined: Jul 2002
Posts: 3,128
Likes: 3
From: Deltona (son of Deland and DAYTONA) FL
Re: What are these things? (ice pac)
Yeah,
I have the 2 switches hanging off my T-stat housing and kinda wished I didn't. I know with a carb that didn't have all that junk to depend on the car would probably run faster.
I hope to be the proud owner of a couple of those plugs one day or at least a new T-stat housing. :yesnod:
I have the 2 switches hanging off my T-stat housing and kinda wished I didn't. I know with a carb that didn't have all that junk to depend on the car would probably run faster.
I hope to be the proud owner of a couple of those plugs one day or at least a new T-stat housing. :yesnod:
Burning Brakes
Joined: Jul 2000
Posts: 1,118
Likes: 0
Re: What are these things? (paul79)
paul79: Is there a difference on the 79's compared to the 81's? Mine is an ECS TVS for fuel vapor and just wondering how that co-exists with the EGR. Usually if the canister is good, but getting no vacuum, then you'd check the PCV. I'm probably missing something along the way... too many hoses!! :smash:
Thread Starter
Instructor
Joined: Nov 2001
Posts: 248
Likes: 0
From: Houma LA
Re: What are these things? (paul79)
Yes I'm interested in those numbers but first I have to ask: What are the dangers of running without all the extra stuff? It was mentioned that they could perhaps hinder performance. If it's not a necessity I'll just leave things as they are and keep those holes plugged up.
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Pro
Joined: May 2002
Posts: 726
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From: Petaluma CA
Re: What are these things? (ice pac)
Save those good-looking thermo vacuum switches and rebuild them !
Or ask the parts guy if there is a core charge.
Sorry, it's Saturday night.. :cheers:
There is no great RWHP loss here. EFE heat riser just keeps some hot exhaust for quicker warm-up. EGR just reburns exhaust gases...smog pump blows air into exhaust manifolds and cat to burn all exhaust...
Or ask the parts guy if there is a core charge.
Sorry, it's Saturday night.. :cheers:
There is no great RWHP loss here. EFE heat riser just keeps some hot exhaust for quicker warm-up. EGR just reburns exhaust gases...smog pump blows air into exhaust manifolds and cat to burn all exhaust...
