'77 FJ40 Federal 2F desmog (2 Viewers)

[subzali]

...The distributor functioning is pretty different...78 carbs have an EGR port, an advance port and a TP port. I don't know what an EGR cut port would do. A 78 distributor requires the 78 computer to function to factory specs. That doesn't mean you can't run it but the distributor should be recurved and you would only need a line from the advance port on the 78 carb to the vac. adv. can on the 78 distributor.

It looks like the advance port on a '78 carb would be roughly equivalent to the EGR cut port on a '77 (comparing this diagram posted by Jim C. of a '78 desmog setup with the diagram at the beginning of this thread):

My '79-'80 dizzy has two vacuum ports, and is a dual-vacuum advance dizzy. I'm not sure which diaphragm is primary and which is secondary in this setup, but I know on some dizzies the outer diaphragm is the primary and the inner diaphragm is the secondary, which would typically be connected to the High Altitude Compensation (HAC) valve.

No that's not a fuel bowl vent. I don't remember what Jim C. called it but it has a little flapper valve in there that opens and closes with vacuum. I didn't know that it connects in the way your is - i.e. - to the vacuum surge tank which is a 77 specific smog component and not found on a 78.

I'm pretty sure I inherited my 40 with that hooked up that way. It sounds like it needs to be changed.

The different VTVs seem to bleed off or allow the build up of vacuum at different rates. The different BVSVs open at different operating temps to control when various vacuum-actuated smog stuff comes into play.

That's what I figured, thanks.

You need a 77 and a 78 emission manual to compare how all the above systems work. They will tell you when each system is operational by temp, etc.

Working on getting that together now, thanks.

At this point, with the new information I've learned so far, I'm inclined to put the smog stuff back on. Unfortunately I've taken a liking to my fully electronic ignition system (no points adjusting), so it would be nice if I could make my '79-'80 dizzy and '78 carb work with the '77 emissions system. It would be really cool if all that took was to take the advance can from the dizzy and plug it into the advance port on the carb, then all my vacuum ports would be hooked up to something

 

[FJ40Jim]

Subzali,
The pictured carb is 1978 2F USA.

The pictured dissy is 79-80 dual vac advance.

Metal box on the top of the carb is the HIC valve. It should connect to the fitting on the top front of the carb (as shown). The lower vac hose off the HIC should run down to a fitting that is a little hard to see, on the side of the carb insulator base.

 

[subzali]

lol, guess I should just start over then huh...just take it back to stock '77 components, ignition, dizzy, carb, points and all?

 

[subzali]

Metal box on the top of the carb is the HIC valve. It should connect to the fitting on the top front of the carb (as shown). The lower vac hose off the HIC should run down to a fitting that is a little hard to see, on the side of the carb insulator base.

Jim, are you saying the hose to the HIC valve should connect to one of the ports pictured here?

Or which side of the carb is this fitting located on? Oh, and what does HIC stand for? Hot Idle Compensator?

Thanks

 

[FJ40Jim]

Yes, Hot Idle Compensator.

The lower hose from HIC connects to a vac tube that is molded into the insulator block underneath the carb. On the outside of the engine, opposite side to the above carb pic.

On the far side of insulator #2 in this pic:

 

[subzali]

Thanks Jim. It looks to me like that's basically a manifold vacuum port, so since I'm not sure if my '77 has that port on the carb insulator base (assuming mine's still from a '77, I'd have to check), would connecting the HIC to the gas filter be a close enough approximation to the manifold vacuum it wants to see to make it work "properly," if I can use that word here? I know the right answer probably is that I need to return my carb to the correct model year, but for now will it work? Or would it be better to not even hook up the HIC to vacuum and forget about it?

 

[FJ40Jim]

The HIC will leak additional air into the manifold fitting when hot, to raise & stabilize the idle. Therefore that air needs to be admitted right at the center of the manifold. If it is added at the manifold vac fitting in front of the carb, most of the additional air will go to the frt 2 cylinders, making them lean & stumbly.

For now, just remove the hoses from the HIC valve and cap the fitting on the air horn.

 

[Slow Poke]

Is the HIC on a stock 77 or is it from his 78 carburetor? Is the HIC labeled in the above pic?

 

[subzali]

The HIC started in '78 and is not stock in '77. Since I have a '78 carb that's where it comes from. It's the box in the upper right hand part of the picture in post #24. I'm pretty sure I'm going to have to cap it off since I don't believe I have a '78 carb insulator base on my truck.

 

[Slow Poke]

How's it idle when hot? Mine has a little stumble. I think it runs a little lean. I'm almost totally desmogged except for the charcoal canister portion.

 

[subzali]

Jim says that the HIC allows a little more air in the intake at hot idle to increase the idle speed and help with the stumbling. I'm not sure mine is making any difference, the way it's hooked up currently. I don't necessarily notice any stumble though either. I'll see if anything changes once I cap off the HIC valve. I can't say I'm very sensitive to that kind of stuff though, especially on an older vehicle that is not nearly as tuned and smooth as a modern engine.

 

[snowpusher]

It's a new year Subzali. How's the project coming?
I have a '78 FJ40. Original owner, original parts ...
Not if, but when you have successfully completed your project ...
I would be interested in letting you help me do mine
in a fraction of the time ... It's my primary vehicle ...
so I cannot have it disabled for long.
I hope that is not asking too much.
Is there anyone else in the Denver area with some positive experience with all of this,
or are you going out on a limb, solo, with diagrams, long threads ... and essential info from FJ40Jim ???

 

[subzali]

Honestly after listening to all these guys on MUD I'm inclined to keep it stock with all the smog stuff. The only thing I'm worried about is the smog pump seizing up, and if there are any compatibility problems with my '79-'80 distributor and '78 carb and my '77 emissions equipment.

With you being in the Denver area, you probably need to have emissions testing every other year unless you've been grandfathered in to the Collector's Vehicle program (i.e. you've had collectors plates already issued for your vehicle which have the 5-year no-emissions registration). And like someone said earlier in this thread, at some point that leniency may even go away as well. So it would probably be better to keep all your smog equipment and keep it in good running order.

I don't have an emissions diagram for a '78 (it's different than a '77), but Jim C. posted a desmogged one that I put in post #21 of this thread. Funny with all the FJ60s that seem to go through the desmog process it's not talked about much in the FJ40 section. That said there are a few that have done it, feel free to post up on the Rising Sun forum for local help:
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or come to a meeting, our monthly meeting is the 1st Wednesday of every month at Stevinson Toyota West (in Golden) at 7:30 (come early to kick tires); our first meeting of 2011 is this Wednesday! I'm sure some folks who have traveled this path before wouldn't mind giving their opinions!

 

[subzali]

I have a question about the power valve. It appears to me that:
'75-'76 had external vacuum ports for the power valve.
'77 and '78 do not.
'79 - '87 have a reintroduced port in the same location (air horn), but it sounds to me from my reading that it doesn't function to serve the power valve.
California models may be a little different.

Anyway, whether or not any of that is true, I'm wondering what controls the power valve on '77 and '78 carbs? Is there an internal vacuum source in the carb? My 2F repair manual shows the power valve with an external vacuum connection (it also shows an AAP, which I do not have either, seeing as it is a '75 USA-only thing ). A lot of reading over the past couple of days has not yielded any conclusive results for me. I saw a thread that indicated it is electronically controlled on a '78, but wasn't sure how that was accomplished, and wasn't sure if that was the same case for a '77 either.

Another question. What is decel fuel cutoff and how is it controlled? Is it applicable to my '77 model year and/or to my '78 carburetor that the PO provided me with?

Thanks,

 

[FJ40Jim]

The PV is internally connected on most carbs, except for the 75-76 USA models.

Decel fuel cut is on 79-newer USA trucks with a 2-wire ICS.

 

[subzali]

Perfect, thanks for the info Jim!

 

[snowpusher]

Thanks for the response subzali. I am in Grand Lake, two hours away from Denver and do not come down much. I will look into joining your club. I'm still interested in doing the desmogging. I have never had to do any emissions testing and still have my original Grand County license plates from when I bought the '78 FJ40 in February of 1979. I am going to write to Jim C (C for Curmudgeon) and order what parts I can and figure out when I can send him my carburetor. I have all original equipment with no modifications.
Had 33 below zero a week ago ... been getting dumped on with snow. I have an old-time mechanic buddy coming up to visit at the end of February. If it's warm enoungh to do it outside, will try to install some ARB lockers. I just bolted in the air compressor today. I chose to mount it inside behind the front passenger seat, so that the compressor will not be freaking cold and freeze up when I need it the most. I still need to fix some air and or exhaust leaks under the hood. Will try to get everything tightened up and engine health checked before I start into the desmogging process.

 

[yachtranger]

Great Diagram

Great diagram, did it work? I'm sitting in front of my 77 FJ dying to clean up the smog mess but wanted to make sure your diagram worked out for you.

 

[duffontap]

Great diagram, did it work? I'm sitting in front of my 77 FJ dying to clean up the smog mess but wanted to make sure your diagram worked out for you.

I happen to be in the market for a '77 federal smog mess if anyone is looking to rehome one

 

[subzali]

Great diagram, did it work? I'm sitting in front of my 77 FJ dying to clean up the smog mess but wanted to make sure your diagram worked out for you.

Well it certainly cleaned the engine bay up. As far as everything else goes, it's hard to say. I didn't notice any differences, but then again I just found out the other day that my secondary has not been working for the past 6 1/2 years since I bought the Cruiser

Shows how much I know

Actually I'm looking to reassemble my smog components as well, because it is required in my area and I just can't help but think I'll need it again someday. I need a BVSV (blue), VSV, and VTV (red) to get back crankin' again. And then I have to figure out what to do with my later distributor and '78 carb...

It may be unrelated, but my exhaust is pretty stinky now