1977 fj40 vacuum system help!

[moogieman]

Im not sure what the previous owner did, but a technician told me that it was kind of funky in my engine how my hoses were connecting, and also that there was a part missing (some kind of air unit?). Im not an expert at it, but he recommended that I upgrade the entire thing into a weber carb kit with electronic ignition (something like that). Anyhow, I just wanted to get some opinions before doing so, as I would like to keep my baby stock if at all possible.

Im wondering if the PO was desmogging it, or if there is really a problem at all?

Thanks!

James

 

[moogieman]

vacuum pic 1

First picture:
1. Is this supposed to be plugged? Do I have the wrong air filter unit for a 1977?
2. These three hoses, are they supposed to be going to nothing and just open like this?
3. I am looking for the hose and airscoop for this. No questions really I guess

 

[moogieman]

vaccum pic 2

vacuum pic 2

4. this hose is going to nowhere, is this supposed to be like this?

 

[moogieman]

vacuum pic 3

5. this is where the tech told me that there should be some kind of air unit, not sure what it was but he said it was missing entirely. As I said, not sure if the PO desmogged this or what and it wasn't needed, but no one likes to hear that an entire part is missing :I

 

[moogieman]

vacuum pic 4

6. Is this little nub not supposed to be connected to anything?

 

[moogieman]

vacuum pic 5

7. What is supposed to go in this clamp?
8. What is this thing? A smog sensor?

Im a bit confused as well, I thought the smog stuff didnt occur until 1978 and mine is a 1977. Although I have to say, im new to this, but Im trying to get her ready for a summer roadtrip from Virginia to Austin and hopefully California!

Thanks all

James

 

[cliffrdavis]

Moogie, first start searching Jim C's threads, find his desmog diagram and figure out if that's what your PO did. Is your 40 running rough, why did you see a technician?This isn't something to start tinkering with to see what works...

There are lots of poorly done desmogs out there. I did one last year, mine was also partially done by PO. IMO there are three good options: weber, Trollholes stock desmogged carb(what i did), and Jim C's conversion Jim C is the desmog expert on Mud and he converts stock aisin carbs to good running desmogged carbs.

First, if it runs well don't screw with it. If it runs poorly, get an emission book on your vehicle (PDFs versions available on Mud), do lots of research on what you are missing and what you are going to remove.

Drop me a PM tomorrow and I'll flip through my emissions diagrams and desmog pics and tell you as much as I can from your pics.

Most importantly, assure if you desmog that your vehicle won't have to pass emission testing!! Nothing worse than spending time and money and not being able to get it to pass inspection.

Cliff

 

[moogieman]

Hey cliff

Thanks for the reply. I am not really trying to desmog it, I suspect that it has already been desmogged, or at least tinkered with...I just want to make sure that its done right before I find out on a roadtrip that it hasn't. Im not trying to tinker with it until I have a good understanding of whats going on with it.

Im pretty new to this, and just finished rebuilding my front axle (finally!), and would like to get to know my rig system by system. Unfortunatly, summer is coming and I'm going to hand it over to the local techs to make sure it can do a cross country roadtrip, thats the plan anyhow. They recommended ripping all that stuff out of there and putting in a weber carb, which is slightly costly, but moreso...if i can keep it stock(ish), and it works, then I'd like to pursue that route.

It does run a bit rough, idles rough. Not sure if it just needs a tune up, or if its another issue. Ive been researching and looking at Jim C's stuff and other threads, however a lot of them are a bit over my head, and i think that a lot are for different years. It seems that I am missing the parts that are consistent with a desmog, im just not sure if its all correct or not.

Im hoping that someone out there will be able to tell me 'yes, it was done well', or 'no, it wasnt, but if you connect this hose to that part and get this part etc then it will be good to go'.

Thanks again,

james

 

[moogieman]

https://forum.ih8mud.com/40-55-seri...0-desmog-axle-rebuild-steering-discbrake.html

how do i get to there?

 

[SliderJack]

#5 is the bracket where an air pump would mount and is missing.

 

[subzali]

This thread has some diagrams of the emissions system for a 1977 (Federal):
https://forum.ih8mud.com/40-55-series-tech/440852-77-fj40-federal-2f-desmog.html

First off, yes 1977 is well into the emissions era for FJ40s. You need to see if yours is for Federal emissions or California emissions. Is the sticker on the hood white with black letters or black with white letters?

As you've noticed, yours is missing some things.
-Your air cleaner is for a later model engine. The three ports that are open really should be capped off so that they do not draw air into the carburetor that has not been filtered. #8 did not exist in 1977, but was used in later models and could probably be made to work with the rest of your system.
-Your air pump (sometimes called a smog pump) is missing (#5). It draws air through a hose that is connected to #1. It looks like the discharge hose from the air pump is still attached to the ABV and is just hanging down. Possible reason the air pump was removed may be because it seized.
-#4 should not be disconnected. You need to find out where it needs to go. Could be a source of a vacuum leak if it's not plugged.
-There should also be vacuum control valves and a vacuum surge tank mounted on your driver side fender. I don't see those.

So that'll get you started.

 

[moogieman]

Bout ready to start researching and starting on Berta40 again here soon...Does anyone have any pictures of a desmogged 1977 40 that I could work from? And I am gonna look for all the correct parts that I am missing, starting with the air cleaner that seems to be from a later year on my FJ.

Thank you all for your responses before the break. I was unable to get my 40 ready for a summer road trip, so I ended up buying a new car and throwing 11,000 miles on it. Probably better that way anyhow

To a new year!

 

[moogieman]

Subzali,

I read through a bunch of your threads about your emissions for your 77. Just wondering what you ended up going with and if you have any advice on how to go about it?

Thanks

James

 

[77mustard40]

Bout ready to start researching and starting on Berta40 again here soon...Does anyone have any pictures of a desmogged 1977 40 that I could work from? And I am gonna look for all the correct parts that I am missing, starting with the air cleaner that seems to be from a later year on my FJ.

Thank you all for your responses before the break. I was unable to get my 40 ready for a summer road trip, so I ended up buying a new car and throwing 11,000 miles on it. Probably better that way anyhow

To a new year!

Here are shots of mine, BTW that's a 76 carb so the vac hookup is different than a 77 carb.

 

[moogieman]

how did you go about your desmog? Was this one done through JimC?

 

[moogieman]

Seems white with black letters? Very old, Im also making an assumption that the hood wasn't replaced.. Does that mean its Federal?

This thread has some diagrams of the emissions system for a 1977 (Federal):
https://forum.ih8mud.com/40-55-series-tech/440852-77-fj40-federal-2f-desmog.html

First off, yes 1977 is well into the emissions era for FJ40s. You need to see if yours is for Federal emissions or California emissions. Is the sticker on the hood white with black letters or black with white letters?

 

[moogieman]

Handdrawn schematic

Using photoshop, I traced every hose and component to where it currently goes on my fj based on the routing 1977 emissions diagram that I found. The green dots mean that the hose is just open ended at that point.

I am now theorizing if the PO (who had a good fj mech), actually desmogged the engine in a beneficial way? But I'm not sure.

- Marked 'A': The (red)VTV1 which has the open end (marked 3) is instead being pretty much replaced by the sensor on the top of my newer year air cleaner, of which I attached a picture and drew a line from on the top of the document. If I take off the hose from the carb to point 3, it just eliminates the (red)VTV1 that is on the hose to the carb. Doesn't seem to make a difference and I wonder if the valve is just closed off?

-Marked 'B': My carb has an extra port at the top that isn't mentioned on the diagram, but is in 77mustard40's picture as well. Its currently going into the VSV.

- My TP seems to be going straight into the EGR port (think I am right on this). --

- I've connected points 1 and 2 together, as it looks like it could have just slipped loose, or it could have been purposefully done. When I connect it together it seems to make the engine rev higher, but only at a higher rpm (when I have the choke on a bit).

It seems like there is logic to how the PO had it done, and ive been crunching the diagrams along with trying to figure out how it all works/ties together. I wonder if it was connected up in a way to bypass a lot of the smog stuff, or render some of the valves 'always closed' , but still make it look like it was smog compliant? I'm not really sure, but I'm trying to trace out another diagram and figure out exactly what this thing is doing.

Any thoughts or direction, greatly appreciated Complicated! But I'm learning a lot. Would like to know how this whole thing works anyhow and then make a decision on either restoring to stock or taking a bunch of this crap off (as it seems many of you have done on here).

Tryin to wrap my head around this...

 

[moogieman]

original diagram

THat I was working from and editing to match what berta has...

 

[Melloj123]

I have a desmogged 77. It was Calif emissions and desmogged when i bought it. Jim C rebuilt my carb 4 years ago and it runs great. No smog pump. Starts first time every time. I would definitely recommend keeping your Aisin carb. I will try to get some pics soon but it is colder than hell here now.

 

[Fast Eddy]

Your air cleaner should work fine assuming it seals well onto the carb.

77mustard40, however, yours is ingesting hot air coming directly off the manifold and from the radiator. You should get a new one that can suck some nice cold air from the front. You will probably notice the difference.