Steve83 Posted September 3, 2019 Posted September 3, 2019 Not perfect but I’m close. I’m unsure as to how the vacuum is affected by the temp switches at the thermostat housing. Im getting no/weak vacuum with a warming engine if I put my fingers over either tube connecting to the side of the air cleaner ( which Coincidentally is labeled TVS on the inside matching with the schematic). There appears to be two temperature switches in the circuit With the thermactor and egr. How do they interact? It’s idling very rough- almost stalled twice, so much so I actually had to feather the gas for a while before would stay on. Thoughts? Could this now be due to a bad egr? This is a list of abbreviations that can be searched (on a computer) by pressing CTRL+F and then typing in what you're searching for: http://www.fourdoorbronco.com/board/showthread.php?5226-Terms-amp-Abbreviations For check valves, black goes to the intake manifold vacuum: https://supermotors.net/getfile/831134/thumbnail/vckv.jpg To diagnose a failed EGR valve, loosen the carb mounting nuts enough to slip a sheet of Aluminum foil in blocking the EGR journals temporarily, and tighten it back down. This is rotated the way you see it standing at the front bumper: https://supermotors.net/getfile/1153082/thumbnail/veci81351m.jpg The one on the lid is the air cleaner bimetallic valve (A/CL BI MET). The one on the side is the thermal vacuum switch (TVS).
LARIAT 85 Posted September 3, 2019 Posted September 3, 2019 To make it easier to read: Going by your diagram, you should have a vacuum hose from the vacuum motor riveted on top of the snorkel, which is called an Air Cleaner Diverter Valve, or A/CL DV. In this hose is a delay valve, which is called a Vacuum Regulator Delay Valve, or VRDV . From there, the hose should connect to a two-port valve on the air cleaner lid, which is called a Air Cleaner Bi-Metallic Valve, or A/CL BI MET. On the other port of this valve, there should be another vacuum hose that connects to the intake manifold, or INT MAN. It looks like you now have the air cleaner snorkel connected right to allow the thermostatic air cleaner to regulate warm air and/or cold air into the carburetor. (At some point, you will need to re-tune the carburetor with the air cleaner in place and fully warmed up.) The white two-port valve sticking out the side of the air cleaner is called a Thermal Vacuum Switch, or TVS. Going by your diagram, one port has a hose connected to a vacuum source located on the carburetor. Since it is in the EGR circuit, I bet that is a *ported* vacuum source. This means it only works above idle. The other port has a hose with a tee in it. One end of the tee connects to another Vacuum Delay Valve (VDV), through an inline vacuum restrictor (V REST), and then to the EGR valve. The other end of that tee connects a Vacuum Retard Delay Valve (VRDV) and then to the thermactor Air Bypass Valve (AIR BPV). I was wrong on the choke. Your fresh air tube connects to the carburetor air horn like I (and FuzzFace) said, but the other end connects to a plate bolted on the intake manifold. Your truck has a "hot water" choke, in that the choke opening corresponds with engine coolant temperature. The [insulated] hot air tube also connects to this plate and back to a metal fitting that screws on the bottom of the carburetor, right at the choke cap. I can see it connected to the choke side, but I can't tell if these tubes are connected to the plate on the intake manifold on your truck. These are known to rust off there. Check and see. If they are rusted off at the plate, your choke is not going to work correctly.
Whisler Posted September 3, 2019 Posted September 3, 2019 How the air cleaner works is shown here: Fuel Systems/Air Cleaners. And an EGR valve that is not closed can certainly cause problems with the engine idling. And the EGR valve can be open due to getting vacuum when it shouldn't or because there's carbon in it keeping it from closing. I may have an idea as to the confusion here. It seems that some air cleaners had the vacuum/ temperature controller in the lid of the air cleaner (like mine) and some in the side of the air cleaner. Is it possible that delco has the base from one system and the lid from another thus giving redundant systems. It seems that Ford used differing systems on different engines (such as using a choke heater in the intake manifold cross-over for 351W and a different choke heater using exhaust manifold heat on the 302) Just a thought!
delco1946 Posted September 3, 2019 Author Posted September 3, 2019 I may have an idea as to the confusion here. It seems that some air cleaners had the vacuum/ temperature controller in the lid of the air cleaner (like mine) and some in the side of the air cleaner. Is it possible that delco has the base from one system and the lid from another thus giving redundant systems. It seems that Ford used differing systems on different engines (such as using a choke heater in the intake manifold cross-over for 351W and a different choke heater using exhaust manifold heat on the 302) Just a thought! Whew so lots to digest/ address here. Based on these descriptions I can check off the top-of-air-cleaner connections to the snorkel. Up until you just defined “ported” vacuum I had no idea what ported meant on a ported vacuum connection but this makes sense as I have had no vacuum coming out of the carburetor connection going to the TVS on the side of the air cleaner. But then again I have no one pushing the gas pedal. It also doesn’t seem like it matters which side of the TVS I connect the carburetor connection to? It’s either open or closed. I will say that I am not confident that the cylindrical “things” I have in line are vrdv or vdv. Which is what? How do I tell? I also don’t appear to have a restricted (vrest) inline to my egr or on my vcv stem. What does this do and look like? I’ll have to find a part to source either new or from a JY. I do have a yellow cylindrical “thingy” in line from the carb to the vcv, which doesn’t appear to match the sticky. Whistler hit the nail on the head with my earlier confusion. Lariat- Once again with the choke talk you’re losing me but I’m trying to follow. I followed the instruction that I think fuzzface gave? I connected the back of the carburetor to the metal tube that was not connected to anything. That metal tube does indeed go in to the top of the manifold.
Steve83 Posted September 3, 2019 Posted September 3, 2019 Whew so lots to digest/ address here. Based on these descriptions I can check off the top-of-air-cleaner connections to the snorkel. Up until you just defined “ported” vacuum I had no idea what ported meant on a ported vacuum connection but this makes sense as I have had no vacuum coming out of the carburetor connection going to the TVS on the side of the air cleaner. But then again I have no one pushing the gas pedal. It also doesn’t seem like it matters which side of the TVS I connect the carburetor connection to? It’s either open or closed. I will say that I am not confident that the cylindrical “things” I have in line are vrdv or vdv. Which is what? How do I tell? I also don’t appear to have a restricted (vrest) inline to my egr or on my vcv stem. What does this do and look like? I’ll have to find a part to source either new or from a JY. I do have a yellow cylindrical “thingy” in line from the carb to the vcv, which doesn’t appear to match the sticky. Whistler hit the nail on the head with my earlier confusion. Lariat- Once again with the choke talk you’re losing me but I’m trying to follow. I followed the instruction that I think fuzzface gave? I connected the back of the carburetor to the metal tube that was not connected to anything. That metal tube does indeed go in to the top of the manifold. You seem to be jumping all around randomly, which is going to cause confusion - for you, and everyone else. I suggest you pick ONE vacuum circuit, find its pieces, connect them properly, post pics of it if you want more opinions if you got it right, and then move to ONE other circuit. Most of the components look similar: flat cylinders with nipples on each end. They're color-coded for function, size, & timing, but I don't know all the codes. Restrictors & delay valves aren't critical; if either is missing, just connect a vacuum hose between the next 2 things, and keep going. A restriction can be created with a piece of tape over a nipple, and a pinhole in it, followed by connecting the vacuum hose. According to your VECI map, the ported vacuum (PV) nipple is supposed to be connected to the manifold, so I'd leave it that way. Once you get the vacuum lines sorted, adjust the carb by the instructions on the label. Timing, too.
delco1946 Posted September 3, 2019 Author Posted September 3, 2019 You seem to be jumping all around randomly, which is going to cause confusion - for you, and everyone else. I suggest you pick ONE vacuum circuit, find its pieces, connect them properly, post pics of it if you want more opinions if you got it right, and then move to ONE other circuit. Most of the components look similar: flat cylinders with nipples on each end. They're color-coded for function, size, & timing, but I don't know all the codes. Restrictors & delay valves aren't critical; if either is missing, just connect a vacuum hose between the next 2 things, and keep going. A restriction can be created with a piece of tape over a nipple, and a pinhole in it, followed by connecting the vacuum hose. According to your VECI map, the ported vacuum (PV) nipple is supposed to be connected to the manifold, so I'd leave it that way. Once you get the vacuum lines sorted, adjust the carb by the instructions on the label. Timing, too. Steve - the pv connection to manifold that you speak of is there/ present. I found a couple references suggesting that the coloring of the retard and delay valves indicates how long it will delay the vacuum, which makes a lot of sense. It sounds like these impact the timing of the vacuum whereas restrictors do not, while simultaneously modulating flow via a restricted opening. Im guessing the restrictor governs once the delay timing feature is "exhausted". I dont think this is for Ford, but i bet the principal is similar:
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