To the Desmog guru's, is this the correct vacuum routing for a desmogged 1977 FJ40?
Any help would be greatly appreciated.
Any help would be greatly appreciated.
77' FJ40 - 2F Desmog - Correct vacuum routing
- Thread starter GA Architect
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- #2
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I have a desmogged 77. I will post pics of the correct vacume routing when I get home from work. Hope it helps.
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Thanks, any help with photos would be great.
Hope this helps. Let me know if you need better/different angle pics.
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A few more
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Capt. M:
1. Where does the vacuum line off the exhaust manifold run too?
2. I take it that your dizzy vac line runs to the #13 - EGR cut port. (Per my photo, it would be in the yellow circle)
I wish my carb was that clean.
Thanks
1. Where does the vacuum line off the exhaust manifold run too?
2. I take it that your dizzy vac line runs to the #13 - EGR cut port. (Per my photo, it would be in the yellow circle)
I wish my carb was that clean.
Thanks
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Looks like a thermo sensor into the intake manifold just under and to the left of the secondary diaphragm--do you know the thread size and the connections for it? My 77 has a plug there--thinking I could use it for a vacuum sensing port---
BTW that is a very clean looking install!
BTW that is a very clean looking install!
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- #9
Captain M,
I have my distributor vacuum line connected to port #13. Here are a few photos showing the before smogged engine bay and the after desmogging engine bay. Thanks for you help.
Now the after photos:
That looks like a diagram pulled from my thread about desmogging. Best I could figure your line from the dizzy should go to port 13 on the carb. A 77 federal carb shouldn't have a vacuum port on the top front. If it does you need to figure out what it's for. If you happen to have an older carb it may be a power valve connection which you will want to hook up to vacuum.
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^^ this. Dizzy to port 13. Subzali is the one who helped me with my desmog.
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- #12
I'm not sure why my 77' carburetor has that port in the front. I have looked at all the carbs on SOR and none look exactly like mine. If that port needs to be hooked up to vacuum, can I add a line from the capped off exhaust port (fuel something) up to top port on the carb?
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- #13
subzali,
Yes the diagram I used was yours. The reason for this thread was that if you look at the original routing of the distributor vacuum line, it basically runs into port #5 along with a "T" connection from the VCV #2. But for your desmog diagram, you ran the distributor vacuum line into port #13.
As for the extra port at the top of my carb, it appears that some of the 77' carbs had the extra port? I've seen this mentioned in two other threads. Moogieman mentioned his 77' had it as well as 77mustard40 has it, but not in the same location. I can't figure out what it is for.
NOTE: When I got my 40 back from desmogging, the vacuum line routing had the distributor line running into one of the exhaust port and then the other exhaust port into that top port of the carb. Then the charcoal canister was hooked into the VSV and one VSV port was hook into the TP diaphragm, and the other VSV port open. The Blue BVSV was left open and the two ports (#5 & #13) were left open. I just didn't think that was right, thus this thread.
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- #14
subzali,
I believe that odd port near the top of my 76'/77' carb has to do with it possibly being a High Altitude carb? It was originally purchased in Colorado in August of 1977. I've seen another photo from BOSOXFJ40 here on MUD that had the exact same carb on their 77' FJ40. If this is the case and being that my rig is located in GA now closer to sea level, I think it can be capped.
Ah yes, the high altitude 77. nattybumpo here in CO has one of those and I keep forgetting about that configuration. Not sure what the port is for. CA-model 77s also have a port high on the front of the carb, not sure if it's a bowl vent or power valve or other. Jim C would know.
I'm a little rusty on all this, so you will probably want to check your FSM to be sure. My truck has a '78 carb, so I had to figure out which port provided the best vacuum source for my distributor. In my case it is port #13. Not sure if a '77 carb is the same; I've been on the lookout for a '77 builder carb but have been unsuccessful finding a cheap one. It may very well be that in a stock '77 configuration port 5 would be a better choice. You can always try both and see what happens. It probably won't make a noticeable difference either way.
I'm a little rusty on all this, so you will probably want to check your FSM to be sure. My truck has a '78 carb, so I had to figure out which port provided the best vacuum source for my distributor. In my case it is port #13. Not sure if a '77 carb is the same; I've been on the lookout for a '77 builder carb but have been unsuccessful finding a cheap one. It may very well be that in a stock '77 configuration port 5 would be a better choice. You can always try both and see what happens. It probably won't make a noticeable difference either way.
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- #16
Thanks for the response. I've tried both port #5 & #13, and they both seem to work just fine. I believe all that matters is that the distributor port is hook to a vacuum port.
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- #17
Matt,
Just found the thread about reading the FJ40 carbs manufacture date stamp, and it discussed a few high altitude carbs specific to the 77's. Per Jim C., it carries the part number: 21100-61090 HIGH ALTITUDE SPEC. (08/1976 - 08/1977)
What is the date code on your carb? Just so we know for sure. 5 and 13 I think are drilled at slightly different positions so the vacuum response may be slightly different between the two. Technically.
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- #19
It's going under the torch right now, having a new OME lift installed and new Dura Trac's put on my widened OEM factory rims. Worked a deal with Toyota, and they said every bolt on the original suspension had to be cut off. Good thing they accepted to do it, I have no cutting torch. Should get it back tomorrow and I'll reply back with the carb code.
Thanks for you help.