desmog and carb help! (1 Viewer)

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Wheaton Illinois
Hi everyone and thank you in advance for any help you can offer.
2 parts to this post so hopefully you can be patient with me and I will do my best to be brief.

First up is desmog:

A little background: 1976 FJ40 that I recently discovered a fuel leak around the site glass. Thought it may be time for a carb rebuild as I always suspected (5 years owned) that it could run better. Had a bunch of concerns about the carb date and spoke with Jim C. He looked at a couple pics I sent him and he confirmed I have a non US carb and a vac advance dissy which he thinks are a “good” combo although not original to the vehicle. He suggested finishing the PO’s desmog, check the timing, etc. and then determine if it needs a rebuild. So ordered the desmog plugs to pull the air rail (smog pump had already been removed and several vac lines plugged with screws!

So pulled the carb off, plugged the holes, but now what do I do with the items in the following pics?

IMAGE1.JPG
IMAGE2.JPG


Second:

So with the purchase of this vehicle came another Aisin carb in a box of misc stuff. My thought was maybe I could throw this carb on and run it while I get in line with Jim C for a rebuild of the other carb. It is a different model (date code 6E6? So maybe the original carb to the vehicle?) Figured what do I have to lose. Since I had the other carb off to remove the air rails, I bolted this one on and tried it. Fired right up and ran better than it ever has. With one exception… When I returned from a quick test ride and opened the hood, there was gas dripping from the EGR tube at the base of the carb? So, would there be any harm in swapping the base plate from the current carb with the plate with no EGR tube onto the other carb? Should there ever be a reason to see gas dripping from this tube? I believe it connects openly to the inside primary side of the base I guess I am not shocked to see fuel here.

carb2.JPG


Thank you taking the time to read thru this and offer any insight that you can.

Mark
 

Dizzy

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The other carb is a federal '75. You will need to plug the EGR inlet. You can't mix the carbs without dealing with choke linkage, etc.

I'm desmogged; '75. I don't know which is the port for your distributor. Connect the choke breaker (external non-USA) to manifold vacuum on the radiator side, plug the other hole next to it. Plug the barb on the manifold middle.

I won't pretend to comment with expertise about gas tank vapors. I have it venting to atmosphere at the fuel cap with a strategic, tiny hole, and a filter on the 6mm hose on the driver side after the hardline (before VSV).
 

1911

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There are some good threads on de-smogging a 2F. The best one is in the 60-series forum, so for late 2F's, but still largely applicable:

My Desmog Keeping HAC Lots of Pics

When I de-smogged mine, I found this Jim C.-blessed schematic to be very helpful. It shows everything you want to keep, and where it is hooked up:

desmog schematic.jpg


Note that the "plug these" in your photo above is the "gas filter" in this schematic. The air cleaner is in the upper left of the schematic. The BVSV shown above the carb is actually located in the thermostat housing.
 
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Wheaton Illinois
The other carb is a federal '75. You will need to plug the EGR inlet. You can't mix the carbs without dealing with choke linkage, etc.

I'm desmogged; '75. I don't know which is the port for your distributor. Connect the choke breaker (external non-USA) to manifold vacuum on the radiator side, plug the other hole next to it. Plug the barb on the manifold middle.

I won't pretend to comment with expertise about gas tank vapors. I have it venting to atmosphere at the fuel cap with a strategic, tiny hole, and a filter on the 6mm hose on the driver side after the hardline (before VSV).
Thanks, can you comment on what you mean about the choke linkage on the other carb? They look identical to me? Also, what are your thoughts on routing the line from the canister into the air cleaner. I think I read a thread somewhere that someone suggested that. Thanks again on all the replies!
 

Dizzy

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I wouldn't do canister into the air cleaner, it is where the valve cover needs to source fresh air, and you may not want those vapors there. There is also a slight possibility of intake backfire. Again, I don't really know with any degree of expertise. I could show you how I made a hole in the OEM gas cap if you are interested, my evap system is plugged so I had to do it this way.

The two carbs are a bit different in height (EGR inlet on the federal one)? So the mix-and-match is probably not going to work. Also, the vac source for the power valve is on the air horn barb on the '75 USA carb.

If you need a three-barb gas filter, I can send you one. It will allow you to run three external carb vac sources (Auxiliary Accelerator Pump, Choke Breaker, and Power Valve) on the '75 carb. It is also nice to have when measuring vacuum.

You can get a 10mm socket cap screw (I think), and some 16mm PCV tube (double check those numbers if you are going shopping) to effectively make an EGR inlet tube cap. The socket cap screw fits into the tube up to the face of the inlet tube, and it is secured with a couple of hose clamps.

EGR Plug.JPG

(above, three-barb gas filter, and EGR delete plug)

Measure the height of the two carbs for air cleaner purposes.

Also, if you are going to retire one of those carbs for an extended period, I recommend a partial disassembly to get the gas out of the passages and bowl, so you don't need to deal with a varnish like substance later.
 
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The installed carb lacks the external control of the power valve, so it is not likely a US model as Jim C says. I would take Jim’s word on it.
The spare carb has it so it is more likely the original, except it has a later model sight glass cover.
The desmog diagram is for later FJ40/60s with a catalyst and do not apply to a ‘76.
You will want to keep the VSV and the lines that vent the Charcoal canister and fuel tank so your cab won’t stink of gasoline.
Fuel dripping from the EGR tube is strange, because this hole should be plugged or it will be a massive leak into the primary. If it is dripping at idle, it suggests that the fuel is coming from the main nozzle, which is an indication of a manifold vacuum leak / Idle fuel problem.
 
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I wouldn't do canister into the air cleaner, it is where the valve cover needs to source fresh air, and you may not want those vapors there. There is also a slight possibility of intake backfire. Again, I don't really know with any degree of expertise. I could show you how I made a hole in the OEM gas cap if you are interested, my evap system is plugged so I had to do it this way.

The two carbs are a bit different in height (EGR inlet on the federal one)? So the mix-and-match is probably not going to work. Also, the vac source for the power valve is on the air horn barb on the '75 USA carb.

If you need a three-barb gas filter, I can send you one. It will allow you to run three external carb vac sources (Auxiliary Accelerator Pump, Choke Breaker, and Power Valve) on the '75 carb. It is also nice to have when measuring vacuum.

You can get a 10mm socket cap screw (I think), and some 16mm PCV tube (double check those numbers if you are going shopping) to effectively make an EGR inlet tube cap. The socket cap screw fits into the tube up to the face of the inlet tube, and it is secured with a couple of hose clamps.

View attachment 2312707
(above, three-barb gas filter, and EGR delete plug)

Measure the height of the two carbs for air cleaner purposes.

Also, if you are going to retire one of those carbs for an extended period, I recommend a partial disassembly to get the gas out of the passages and bowl, so you don't need to deal with a varnish like substance later.
That looks like a great idea for plugging the EGR tube! Much easier than trying to swap the plates. Just checked the height of the carbs and appear to be very close (within 3/16 inch from my quick look with a measuring tape).
As for th 3 barb gas filter, I would gladly take that off your hands! Can I pm you an address and if you need something for it, let me know?
Good call on draining the gas too.
 
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The installed carb lacks the external control of the power valve, so it is not likely a US model as Jim C says. I would take Jim’s word on it.
The spare carb has it so it is more likely the original, except it has a later model sight glass cover.
The desmog diagram is for later FJ40/60s with a catalyst and do not apply to a ‘76.
You will want to keep the VSV and the lines that vent the Charcoal canister and fuel tank so your cab won’t stink of gasoline.
Fuel dripping from the EGR tube is strange, because this hole should be plugged or it will be a massive leak into the primary. If it is dripping at idle, it suggests that the fuel is coming from the main nozzle, which is an indication of a manifold vacuum leak / Idle fuel problem.
Thanks for the info. So if I keep the VSV and the canister plugged into it, I assume I need at least a single vac line going into the VSV, right? Does it matter where I pull the vac line from? and which port on the VSV would it need to go into?
As for the fuel dripping, it didn't seem to do it on idle. It was after a short drive (~4miles at max speed of 45) and I had taped up the end of the tube for the test drive. It was leaking past the tape after the drive is when I noticed it.
BTW, I have watched your youtube videos on carb rebuild. They're awesome. You make it look so easy! Just not sure I have the confidence to pull that off!
 
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You need to keep the line that vents the cannister into the manifold vacuum too. You can find it on the diagram for the VSV in the FSM.

You have a spare carb, so you don't have much to lose. It looks pretty clean and shiny, so you may only need a light internal cleaning and make sure nothing is plugged.
 
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You need to keep the line that vents the cannister into the manifold vacuum too. You can find it on the diagram for the VSV in the FSM.

You have a spare carb, so you don't have much to lose. It looks pretty clean and shiny, so you may only need a light internal cleaning and make sure nothing is plugged.
Thanks!
 

Dizzy

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So the spec on the EGR delete plug is a section of 15mm PCV hose. The EGR tube, on the carb, is 16mm in diameter; that is the OD, and not over the barbed/raised section, which, has so far, worked for my carb. I figure that a 10mm socket cap screw will have the head to match the approximate need for the USA EGR carb.

I can send you a piece of PCV when I send you the 'gas filter.' No charge, PM me your info.
 

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