How do I (re-)connect the charcoal canister (EVAP system) on a 1981 4.9L? (WAS:Carb Tubing Question)
#16
08-06-2011, 07:14 PM
I changed the title of this thread
dancraig,
I changed the title of this thread to something more descriptive in hopes of attracting attention, I know there are people here who know how to hook this up (and Lariat85 might be one of them, I don't know - not trying to squelch him in any way here).
A/CL BIMET = Air Cleaner bi-metallic valve - temperature-actuated, opens or closes the Diverter Valve in the snout
A/CL DV = Air Cleaner Diverter Valve - at the end of the air cleaner snout, gives the carb pre-warmed air (from around the exhaust manifold) or not
INT MAN = Intake Manifold
EGR = Exhaust Gas Recirculation valve - a device between the carb & intake manifold
V CK V = Vacuum Check Valve - allows vacuum to flow in only one direction
AIR BPV = Thermactor (smog pump) bypass valve (I forget what AIR stands for, I think Air Injection sumthin-or-other)
VRDV = Vacuum Retard (I think) Delay Valve
VRESER = Vacuum Reservoir, aka the fruit juice can
DIST = Distributor
PURGE CV *I think* is the Purge Canister valve
TVV, BV, WOT, etc. I forget, sorry
Seems you have two charcoal canisters?
-chris
I changed the title of this thread to something more descriptive in hopes of attracting attention, I know there are people here who know how to hook this up (and Lariat85 might be one of them, I don't know - not trying to squelch him in any way here).
A/CL BIMET = Air Cleaner bi-metallic valve - temperature-actuated, opens or closes the Diverter Valve in the snout
A/CL DV = Air Cleaner Diverter Valve - at the end of the air cleaner snout, gives the carb pre-warmed air (from around the exhaust manifold) or not
INT MAN = Intake Manifold
EGR = Exhaust Gas Recirculation valve - a device between the carb & intake manifold
V CK V = Vacuum Check Valve - allows vacuum to flow in only one direction
AIR BPV = Thermactor (smog pump) bypass valve (I forget what AIR stands for, I think Air Injection sumthin-or-other)
VRDV = Vacuum Retard (I think) Delay Valve
VRESER = Vacuum Reservoir, aka the fruit juice can
DIST = Distributor
PURGE CV *I think* is the Purge Canister valve
TVV, BV, WOT, etc. I forget, sorry
Seems you have two charcoal canisters?
-chris
#18
08-06-2011, 08:40 PM
There should be a colorful diagram on your radiator core support that will explain where all your vacuum hoses should connect. But it can be hard to decipher at first.
The charcoal box, and all the connections coming off of it and to the carburetor is all part of the EVAP (evaporative) system. It routes fumes from your gas tank and carburetor fuel bowl to the charcoal box where they are stored and then back into your engine later for burning. That loose vacuum line should be hooked up somewhere, because right now you have a vacuum leak.
There should be a vacuum connection on the smaller, top fitting of your PCV valve, and there should be one attached to your carburetor (ported vacuum) someplace as well. I can see from your pics that there is vacuum port on the bottom of your carburetor with a piece of black vacuum hose broken off and stuck on the end of it. That black nipple connection might have connected to that hose. Check these places, and your vacuum diagram, and see if any of this helps.
Also, on your charcoal box, the single connection closest to the radiator, there is a hose that looks like it is going down. Where is that hose connected to?
The charcoal box, and all the connections coming off of it and to the carburetor is all part of the EVAP (evaporative) system. It routes fumes from your gas tank and carburetor fuel bowl to the charcoal box where they are stored and then back into your engine later for burning. That loose vacuum line should be hooked up somewhere, because right now you have a vacuum leak.
There should be a vacuum connection on the smaller, top fitting of your PCV valve, and there should be one attached to your carburetor (ported vacuum) someplace as well. I can see from your pics that there is vacuum port on the bottom of your carburetor with a piece of black vacuum hose broken off and stuck on the end of it. That black nipple connection might have connected to that hose. Check these places, and your vacuum diagram, and see if any of this helps.
Also, on your charcoal box, the single connection closest to the radiator, there is a hose that looks like it is going down. Where is that hose connected to?
Although this truck has been in my family almost since new, I have only owned it for about five years. I don't know who put the screw in the PCV connection. I would like to know why they did it when the proper hose is just hanging there. Someone must have thought this was a smart thing to do. Do you know why this is done?
This makes me think my truck starting/running problems are not related to this hose being disconnected. I have checked my plugs, not fouled. I have used some carb cleaner in the carb, I was surprised to find this really helped a lot a couple of years ago. I guess I will drive it around a little later and see how things are.
Thank-you.
#19
08-07-2011, 07:34 AM
The hose you have hanging with the black plastic piece in it, needs to either be hooked back up or pulled off the Vacuum Tree and the port capped. RIght now you are trying to run the motor with a huge vacuum leak, which it probably causing your running issues.
If you can't figure our where it goes then cap it and see if your motor runs better.
If you can't figure our where it goes then cap it and see if your motor runs better.
#20
08-07-2011, 10:06 AM
The reason you have two canisters is because you have two gas tanks. Follow the large hose from your charcoal canister and try to locate the "floating" Purge Canister Valve (PURGE CV) on your truck. It looks very much like the picture of the "PURGE CV" on your emissions diagram. It may be a light green or black color. Follow all of the hoses that are connected to the valve and make sure they connect to something.
According to your diagram, there should be a hose connected from the Purge Canister Valve to the top port of your PCV valve. This connection is where the gas fumes from your gas tank and carburetor fuel bowl are cycled back into your engine for burning. There should not be a screw in it. Someone probably felt that the engine "looks better" with it unplugged, or thought that they were smarter than the Ford engineers. I see this a lot on these older trucks, and some people actually think that they can unplug stuff at will, and that this is supposed to somehow make the engine "run better." Connect that hose back up. It does not cost any horsepower for the EVAP system to operate, and it helps your truck to save fuel and not smell like gas all the time.
You also need a connection from the Purge Canister Valve to the carburetor. This connection is what supplies the vacuum on the Purge Control Valve that pulls the fumes into the PCV valve for burning.
Your truck should *not* have any hoses with screws inside. I would check all of the connections you have that someone put a screw into and either find out where they go or place a proper vacuum cap on the connection to plug it off.
Once you get all that plugged back up, your vacuum leak(s) will be gone. You may or may not have to re-tune your carburetor because there is a good chance the previous owner tried to tune the carburetor with that vacuum leak you have now.
According to your diagram, there should be a hose connected from the Purge Canister Valve to the top port of your PCV valve. This connection is where the gas fumes from your gas tank and carburetor fuel bowl are cycled back into your engine for burning. There should not be a screw in it. Someone probably felt that the engine "looks better" with it unplugged, or thought that they were smarter than the Ford engineers. I see this a lot on these older trucks, and some people actually think that they can unplug stuff at will, and that this is supposed to somehow make the engine "run better." Connect that hose back up. It does not cost any horsepower for the EVAP system to operate, and it helps your truck to save fuel and not smell like gas all the time.
You also need a connection from the Purge Canister Valve to the carburetor. This connection is what supplies the vacuum on the Purge Control Valve that pulls the fumes into the PCV valve for burning.
Your truck should *not* have any hoses with screws inside. I would check all of the connections you have that someone put a screw into and either find out where they go or place a proper vacuum cap on the connection to plug it off.
Once you get all that plugged back up, your vacuum leak(s) will be gone. You may or may not have to re-tune your carburetor because there is a good chance the previous owner tried to tune the carburetor with that vacuum leak you have now.
#21
08-07-2011, 01:22 PM
All that being said, with the hose being loose, you just had gas fumes going into the engine compartment. And since they plugged the hole with a screw, you did not have a large vacuum leak. So I believe you are correct in assuming this disconnected hose is not the real cause of your latest problem.
#22
08-07-2011, 03:40 PM
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The biggest problem with your truck right now is it's not hooked up right at the carburetor.
1: The "E" port on the carb looks like it's going to the Distributor in your picture. It needs to go to the Vacuum Control Valve (VCV) located at the front of the engine. It's in a tee that comes off the thermostat housing and a hose that leads to the heater core. Hook a line from the bottom port of the VCV to the "E" port of the carb.
2: The "S" port of the carb. The lowest one on the carb that looks blocked in your picture. This goes to your vacuum advance on your distributor.
3: With the second from the bottom line on your VCV, hook a line to it that goes to a vacuum tee. Then hook one line from the tee to your Wide Open Throttle (WOT) valve located on the drivers side of the carb, just below the air cleaner, bolted to the carb. It's a small white looking valve with a vacuum port on it threaded to a bracket attached to the carb. The carb throttle linkage has a flat cam that pushes the valve open when it's wide open. Connect the other side of the vacuum tee to the EGR valve.
4: The third port from the bottom of the VCV goes to a vacuum tee. One side of this tee goes to Port "3" on the carburetor the one that is located to the front under the fuel line. The other side of the tee goes to the Thermal Vacuum Switch, (TVS) located on the air cleaner. It's plastic and color coded with two vacuum fittings.
5: The other line coming off the TVS goes to a vacuum tee (I'll call it #T1), one side of the tee goes to a Vacuum ChecK Valve (V CK V) that goes to yet another vacuum tee (that I'll call #T2). The other side of Vacuum tee (#T1), goes to the VRDV (Vacuum Retard Delay Valve) and a short hose to the VRESER (Vacuum Reservoir) that goes to the Air Pumps By Pass Valve (AIR BPV).
6: From Vacuum tee (#T2) hook one end to the Top Port of the VCV, and the other end goes to the Charcoal Canisters Purge Check Valve center port. (PURGE CV) The shortest port of the PURGE CV goes to the Charcoal Canister, and the other Longest Port goes to the PCV valve top port.
This should get your truck hooked up as it was from the factory.
If your truck doesn't have the thermactor system anymore, AIR PUMP, Catalytic Converters, it's valves, or the other components you have listed in the diagram you will need to purchase them to hook it up correctly.
You can eliminate the Thermactor System, (AIR Pump) if it's mostly missing if you prefer, without effecting the other components by removing the vacuum tee that I called (#T1) in step 5, and hooking the line from the TVS directly to the V CK V, then to the vacuum tee I called (#T2) then follow from step six. I don't recommend that unless the system is beyond repair.
1: The "E" port on the carb looks like it's going to the Distributor in your picture. It needs to go to the Vacuum Control Valve (VCV) located at the front of the engine. It's in a tee that comes off the thermostat housing and a hose that leads to the heater core. Hook a line from the bottom port of the VCV to the "E" port of the carb.
2: The "S" port of the carb. The lowest one on the carb that looks blocked in your picture. This goes to your vacuum advance on your distributor.
3: With the second from the bottom line on your VCV, hook a line to it that goes to a vacuum tee. Then hook one line from the tee to your Wide Open Throttle (WOT) valve located on the drivers side of the carb, just below the air cleaner, bolted to the carb. It's a small white looking valve with a vacuum port on it threaded to a bracket attached to the carb. The carb throttle linkage has a flat cam that pushes the valve open when it's wide open. Connect the other side of the vacuum tee to the EGR valve.
4: The third port from the bottom of the VCV goes to a vacuum tee. One side of this tee goes to Port "3" on the carburetor the one that is located to the front under the fuel line. The other side of the tee goes to the Thermal Vacuum Switch, (TVS) located on the air cleaner. It's plastic and color coded with two vacuum fittings.
5: The other line coming off the TVS goes to a vacuum tee (I'll call it #T1), one side of the tee goes to a Vacuum ChecK Valve (V CK V) that goes to yet another vacuum tee (that I'll call #T2). The other side of Vacuum tee (#T1), goes to the VRDV (Vacuum Retard Delay Valve) and a short hose to the VRESER (Vacuum Reservoir) that goes to the Air Pumps By Pass Valve (AIR BPV).
6: From Vacuum tee (#T2) hook one end to the Top Port of the VCV, and the other end goes to the Charcoal Canisters Purge Check Valve center port. (PURGE CV) The shortest port of the PURGE CV goes to the Charcoal Canister, and the other Longest Port goes to the PCV valve top port.
This should get your truck hooked up as it was from the factory.
If your truck doesn't have the thermactor system anymore, AIR PUMP, Catalytic Converters, it's valves, or the other components you have listed in the diagram you will need to purchase them to hook it up correctly.
You can eliminate the Thermactor System, (AIR Pump) if it's mostly missing if you prefer, without effecting the other components by removing the vacuum tee that I called (#T1) in step 5, and hooking the line from the TVS directly to the V CK V, then to the vacuum tee I called (#T2) then follow from step six. I don't recommend that unless the system is beyond repair.
#23
08-07-2011, 04:00 PM
Here's a good site if you ever want to decipher these abbreviations out for yourself. They even have brief descriptions on what some of them do.
Dictionary of Automotive Terms A-Z
Dictionary of Automotive Terms A-Z
#24
08-07-2011, 04:10 PM
The biggest problem with your truck right now is it's not hooked up right at the carburetor.
1: The "E" port on the carb looks like it's going to the Distributor in your picture. It needs to go to the Vacuum Control Valve (VCV) located at the front of the engine. It's in a tee that comes off the thermostat housing and a hose that leads to the heater core. Hook a line from the bottom port of the VCV to the "E" port of the carb.
2: The "S" port of the carb. The lowest one on the carb that looks blocked in your picture. This goes to your vacuum advance on your distributor.
3: With the second from the bottom line on your VCV, hook a line to it that goes to a vacuum tee. Then hook one line from the tee to your Wide Open Throttle (WOT) valve located on the drivers side of the carb, just below the air cleaner, bolted to the carb. It's a small white looking valve with a vacuum port on it threaded to a bracket attached to the carb. The carb throttle linkage has a flat cam that pushes the valve open when it's wide open. Connect the other side of the vacuum tee to the EGR valve.
4: The third port from the bottom of the VCV goes to a vacuum tee. One side of this tee goes to Port "3" on the carburetor the one that is located to the front under the fuel line. The other side of the tee goes to the Thermal Vacuum Switch, (TVS) located on the air cleaner. It's plastic and color coded with two vacuum fittings.
5: The other line coming off the TVS goes to a vacuum tee (I'll call it #T1), one side of the tee goes to a Vacuum ChecK Valve (V CK V) that goes to yet another vacuum tee (that I'll call #T2). The other side of Vacuum tee (#T1), goes to the VRDV (Vacuum Retard Delay Valve) and a short hose to the VRESER (Vacuum Reservoir) that goes to the Air Pumps By Pass Valve (AIR BPV).
6: From Vacuum tee (#T2) hook one end to the Top Port of the VCV, and the other end goes to the Charcoal Canisters Purge Check Valve center port. (PURGE CV) The shortest port of the PURGE CV goes to the Charcoal Canister, and the other Longest Port goes to the PCV valve top port.
This should get your truck hooked up as it was from the factory.
If your truck doesn't have the thermactor system anymore, AIR PUMP, Catalytic Converters, it's valves, or the other components you have listed in the diagram you will need to purchase them to hook it up correctly.
You can eliminate the Thermactor System, (AIR Pump) if it's mostly missing if you prefer, without effecting the other components by removing the vacuum tee that I called (#T1) in step 5, and hooking the line from the TVS directly to the V CK V, then to the vacuum tee I called (#T2) then follow from step six. I don't recommend that unless the system is beyond repair.
1: The "E" port on the carb looks like it's going to the Distributor in your picture. It needs to go to the Vacuum Control Valve (VCV) located at the front of the engine. It's in a tee that comes off the thermostat housing and a hose that leads to the heater core. Hook a line from the bottom port of the VCV to the "E" port of the carb.
2: The "S" port of the carb. The lowest one on the carb that looks blocked in your picture. This goes to your vacuum advance on your distributor.
3: With the second from the bottom line on your VCV, hook a line to it that goes to a vacuum tee. Then hook one line from the tee to your Wide Open Throttle (WOT) valve located on the drivers side of the carb, just below the air cleaner, bolted to the carb. It's a small white looking valve with a vacuum port on it threaded to a bracket attached to the carb. The carb throttle linkage has a flat cam that pushes the valve open when it's wide open. Connect the other side of the vacuum tee to the EGR valve.
4: The third port from the bottom of the VCV goes to a vacuum tee. One side of this tee goes to Port "3" on the carburetor the one that is located to the front under the fuel line. The other side of the tee goes to the Thermal Vacuum Switch, (TVS) located on the air cleaner. It's plastic and color coded with two vacuum fittings.
5: The other line coming off the TVS goes to a vacuum tee (I'll call it #T1), one side of the tee goes to a Vacuum ChecK Valve (V CK V) that goes to yet another vacuum tee (that I'll call #T2). The other side of Vacuum tee (#T1), goes to the VRDV (Vacuum Retard Delay Valve) and a short hose to the VRESER (Vacuum Reservoir) that goes to the Air Pumps By Pass Valve (AIR BPV).
6: From Vacuum tee (#T2) hook one end to the Top Port of the VCV, and the other end goes to the Charcoal Canisters Purge Check Valve center port. (PURGE CV) The shortest port of the PURGE CV goes to the Charcoal Canister, and the other Longest Port goes to the PCV valve top port.
This should get your truck hooked up as it was from the factory.
If your truck doesn't have the thermactor system anymore, AIR PUMP, Catalytic Converters, it's valves, or the other components you have listed in the diagram you will need to purchase them to hook it up correctly.
You can eliminate the Thermactor System, (AIR Pump) if it's mostly missing if you prefer, without effecting the other components by removing the vacuum tee that I called (#T1) in step 5, and hooking the line from the TVS directly to the V CK V, then to the vacuum tee I called (#T2) then follow from step six. I don't recommend that unless the system is beyond repair.
#26
08-07-2011, 06:25 PM
#28
08-08-2011, 07:41 AM
Interesting article..When I bought my '84..(351)..I noticed that there were no CCanisters..It has dual tanks. The factory 4 bbl. had been changed to a Holley at some point..and the lines from the old canisters were neatly connected to the carb plate..thereby burning any fumes. Have never had a gas smell..and don't want to buy and install the expebsive canisters..Don't see this as a problem ???
#29
08-08-2011, 08:33 AM
With the stock EVAP system, the fumes are stored in the canister from the gas tank and the carburetor fuel bowls until the engine is READY to burn them. For example, the purge valve does not operate at all during idle, or at wide open throttle. Secondly, it only empties the canister and feeds the fumes into the engine when the engine has reached operating temperature.
