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Ok on my PC and I want to say don't go too crazy on getting all the new parts like the mixture solenoid because this could nickel & dime you to the poor house.
My 81 is a non-feed back system but from the factory did have some electrical and temp switches that were missing and so was the air pump.
I hooked up the valve on the snout to the temp switch on the filter housing and that to a vacuum source. I have not tested this yet, truck is not really running, but it should.
I also have the charcoal can(s),I have 2 because of the duel fuel tanks, hooked up. Mine should have an electric switch that was missing so I have it hooked up like the sticker on the radiator support has it just with out the switch. Same thing I did with the snout valve and why it is "piped" the way I did.
Besides the 2 above, charcoal can & snout valve, the other thing is the hot air tubes for the choke.
Most of our trucks use the hot air and the electric part to help so don't be fooled that the choke has a wire to it also.
Check the bottom of the exh. manifold for a hole like the top that a metal tube should be connected to. Parts stores have a kit to fix this and I think it was under $20 when I got one.
I am not using the stock log exh. manifold, using EFI manifolds, so I had to come up with a way to get hot air to the choke. In place of the metal line I used copper tubing and wrapped it around 1 of the manifolds.
One end goes to the choke and the other to that fitting on the carb with the orange hose.
Here is the stock manifold and I put a wire thru the 2 openings the metal lines connect to.
Kit & tubing I used
This is the fresh air supply to the choke. The copper goes down to the manifold then to the choke. You can see the yellow wire going to the choke also.
Get this piped right, make sure the choke closes when cold so it will start with out spray and we can go from there. Oh cap any open vacuum ports for now so you have no vacuum leaks.
Dave ----
I did a quick l look at my trucks snout valve hook up.
I have the tear shape filter:
My housing has 2 different sensors in the housing. 1 is on the side the other is in the bottom.
Vacuum comes from the carb, black hose in 1 of your pictures, to the bottom sensor, from it to the side sensor then to the snout valve.
I can not tell you if the sensors work or not.
I don't have the tin that fits around the ehx. manifold because I have the EFI ones and they don't use one.
I may try and make something but it does not get that cold for long down here for me to be that worried.
Dave ----
Please post a picture of your egr valve and where it's vacuum line is.
I'm not familiar with the feedback systems. I mean that I don't have documentation on hand for emission systems specific to the feedback systems.
Best guess is this may be your emissions port on the carburetor. Should be ported vacuum. If so it should not have any vacuum on it at idle or WOT. Only under acceleration. If so, the vacuum line from here runs to the TVV on the side of the air cleaner, then to the egr. It will more than likely have a branch that runs to the carbon canister(s).
one from the carb(ported) then the other to the egr. Your systems doesn't run a ported vacuum switch(assuming that latter photo is of YOUR emissions sticker) which only allows vacuum through when the engine is at operating temp. My 82 uses the bimetal valve on top, then this valve together, before the vac motor on the air horn. Yours appears to just have manifold vacuum to the bimetal valve, the the vac motor on the air horn. Should be a check valve between the motor and the bimetal switch.
I'm guess your systems uses the tvv instead of the PVS.
Vacuum motor. When it's cold, vacuum gets redirected to divert air from underneath the airhorn. Should have some kind of ducting connecting to the shroud on the side of the exhaust manifold to draw warm air through the intake to get you up to operating temperature faster and other things.
Is this a picture of the emissions sticker from your truck?
This is your manifold tree, it gives you all the "branches" you need for all your vacuum hookups that require manifold vacuum:
I'd recommend you get a car/truck shop manual for your year that covers emissions if you want to keep this system. Like Dave said, feedback systems have to work in their entirety or you get stuck in limp home mode. You'll suffer from poor fuel economy and loss of power. I think this setup is why most folks think all older trucks get terrible fuel mileage. Most people convert these trucks to non feedback. There are lots of good threads covering it. It would probably be the cheapest option to get your truck running like it should be. The system itself is very simply as far as electronics and computers go. It's almost entirely mechanical. Search around for some of those threads and read up on it and see what you think.
I did a quick l look at my trucks snout valve hook up.
I have the tear shape filter:
My housing has 2 different sensors in the housing. 1 is on the side the other is in the bottom.
Vacuum comes from the carb, black hose in 1 of your pictures, to the bottom sensor, from it to the side sensor then to the snout valve.
I can not tell you if the sensors work or not.
I don't have the tin that fits around the ehx. manifold because I have the EFI ones and they don't use one.
I may try and make something but it does not get that cold for long down here for me to be that worried.
Dave ----
Plastic one in the side? Metal one in the bottom?
I bet that's like mine except my bi met is in the top.
I'd recommend you get a car/truck shop manual for your year that covers emissions if you want to keep this system. Like Dave said, feedback systems have to work in their entirety or you get stuck in limp home mode. You'll suffer from poor fuel economy and loss of power. I think this setup is why most folks think all older trucks get terrible fuel mileage. Most people convert these trucks to non feedback. There are lots of good threads covering it. It would probably be the cheapest option to get your truck running like it should be. The system itself is very simply as far as electronics and computers go. It's almost entirely mechanical. Search around for some of those threads and read up on it and see what you think.
From everything I am reading I think that will probably be the best option down the road. I just want to get her running decent for now.
As long as it is running decent, the rest of the work can get done and then I can come back and gut all of this, put new heads, distributor, intake etc on it and try to bump up the economy and power a bit.
A friend has the sister truck to this one (same month same set up same factory) and his air cleaner and carb is not like mine. Looking at the manual that red rubber hose is for eec controlled non electric choke systems.
Given the fact that so many variations were in these trucks I think the PO put the wrong carb on it and knew the difference was those two hoses so he plugged them. Then he also put the wrong air cleaner on it.
I say this because yes. That is my emissions sticker and it shows the vac from the manifold to the bi met valve to the flapper. No TVV/TVS is on there. BUT I did Mike the vac nipples. The diverter on the snout is 1/4, then the TVS/TVV has one 1/4 and one 3/16, the bi met on top has two 3/16 then the manifold is 3/16. It made me think it may have routed diverter>TVS>Bimetal>vac manifold.
05-03-2019, 04:48 PM
