It sits in front of the intake. It's orange and has 2 lines 1 going to the air cleaner, not sure where the other goes.
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.
identify this part
- Thread starter Babaganoosh
- Start date
original balzer
1/2 ton status
For some reason or another I do know. Its a thermal vaccume valve. In other words it either alows vaccume to pass through or not depending on the temp. If it goes to the air cleaner its gotta be the heat riser valve control.
Inside your air cleaner theres a flap in the intake, under that flap is a metal flex hose that goes to your exahust manifold. In cold weather the flap closes off the cold air intake and takes heated air from around your exhaust manifold. When the engine warms up the orange thing will close and the flap inside the air cleaner will open to alow cold air in.
Do I realy know what Im talking about? Im not POSITIVE, I usualy strip all that kinda stuff off my engines. But Im pretty sure thats what it is.
Balzer
EDIT: by the way the other hose will go to a constant vaccume sorce. That means you have a vaccume leak. With that said you may want to check for more leaks before you start a carb rebuild in your other thread.
Inside your air cleaner theres a flap in the intake, under that flap is a metal flex hose that goes to your exahust manifold. In cold weather the flap closes off the cold air intake and takes heated air from around your exhaust manifold. When the engine warms up the orange thing will close and the flap inside the air cleaner will open to alow cold air in.
Do I realy know what Im talking about? Im not POSITIVE, I usualy strip all that kinda stuff off my engines. But Im pretty sure thats what it is.
Balzer
EDIT: by the way the other hose will go to a constant vaccume sorce. That means you have a vaccume leak. With that said you may want to check for more leaks before you start a carb rebuild in your other thread.
TTT, could someone clarify what balzer mentioned above?
Thanks balzer, I got off the phone last night with mossesburb and he was convinced it was a vacuum leak. Most likely today or tomorrow I will take a look at everything.
Thanks balzer, I got off the phone last night with mossesburb and he was convinced it was a vacuum leak. Most likely today or tomorrow I will take a look at everything.
What do you need clarified? I understand his post.
Kind of hard to tell, but you need at least two hoses on that orange piece, (depends on application how many total, I think GM had up to 4+ hoses on one of those things at one point) and it looks to me like one of the nipples is broken off.
One line will be vacuum from the engine, (the "in" to the valve if you will) one line will feed whatever is being controlled, the "out". If either one is broken off, and nothing is done, (like plugging a line) then it will result in a vacuum leak.
Kind of hard to tell, but you need at least two hoses on that orange piece, (depends on application how many total, I think GM had up to 4+ hoses on one of those things at one point) and it looks to me like one of the nipples is broken off.
One line will be vacuum from the engine, (the "in" to the valve if you will) one line will feed whatever is being controlled, the "out". If either one is broken off, and nothing is done, (like plugging a line) then it will result in a vacuum leak.
pauly383
Daddy383
Mine broke too . So I simplified the system and run everything of ported vacuum without those things , they are temperature controlled , and mainly are for colder climates .
Our temps are pretty consistent in Phoenix , and we hardly need a choke either . Mine passes visual and the sniffer in our local emissions tests .
Our temps are pretty consistent in Phoenix , and we hardly need a choke either . Mine passes visual and the sniffer in our local emissions tests .
With a climate like Phoenix, probably true that they are less needed, but the reason for most of them being temp switched is to ensure the engine warms up quicker. TCC is a big one, usually shut off until the engine warms up. AIR if present is probably also controlled via the TVS. Probably would lead to less effective converter operation under certain conditons.
EVAP could theoretically cause driveability issues if it purges too soon, as it will richen the mixture up, which could cause problems when the choke is operating.
Having never lived in that warm a climate and having a carbed vehicle, no idea how much faster warmup is.
EVAP could theoretically cause driveability issues if it purges too soon, as it will richen the mixture up, which could cause problems when the choke is operating.
Having never lived in that warm a climate and having a carbed vehicle, no idea how much faster warmup is.
pauly383
Daddy383
Dorian , forgot to add for the evap , I went to simpler 70's can , passes the pressure test , and aside from my stall Sunday on something really steep , my truck can still be DD
I just wanted to know if he was correct on calling the orange part a thermal vaccume valve. He mentioned he wasn't 100% positive and was looking for a 2nd opinion.
pauly383
Daddy383
Ported Vacuum Switch . GM may still stock some , and LMC stocks them now .
Thanks Paul.
Ok, here is another question. What does this actually do? I'm stumped.
Ok, here is another question. What does this actually do? I'm stumped.
Last edited:
