1985 stock emissions control (1 Viewer)

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8693 Mabel Drive
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After looking at the emissions control manual, I see that there are definitely some problems with hose routing on my rig. It runs great, so I will probably do nothing at this point, but I would like to make it right. From what I've read on mud, this is not a task for just anyone. Any advice would be appreciated.
 
Edited link:


After looking at the emissions control manual, I see that there are definitely some problems with hose routing on my rig. It runs great, so I will probably do nothing at this point, but I would like to make it right. From what I've read on mud, this is not a task for just anyone. Any advice would be appreciated.
If you can read the emissions manual and you can tell that there are things that are routed incorrectly, then you can do this. I would take tape and start labeling the vac lines and take pictures of everything. Then, using the manual, change what you believe needs to be changed. If it makes your situation worse, you have pictures to get you back to ground zero. Not knowing any specifics makes it impossible to tell you what needs to be done. We need more information for that. But, like I said, If you can read the manual then you're probably able to trouble shoot this yourself. This is actually relatively simple stuff and will help you learn about the truck and how it works. Fixing this yourself is going to increase your confidence and if you're ever out and about and something goes wrong you'll have a better idea of what to do under the hood.
 
Didn’t mean to jump on you on the other thread - just wanted to bring the vacuum hose routing to your attention.

The two visible anomalies on the photo you provided in the other thread are the hookup of the distributor venting hoses and the connection of hoses to the HIC valve under the air cleaner housing.

Maybe fix the distributor venting first since it’s not really highlighted in any manual.

Below is a drawing (schematic) how the distributor venting is supposed to be plumbed. The little plastic VCV that’s clipped under the air cleaner housing has letters embossed next to each of its pipes. You can use that to cross reference your plumbing against the drawing below.

The thread linked below also has information on the VCV since most of them now are malfunctioning.



92F0EBCA-6954-427D-981A-3227D6BD7F84.png
 
@robcgray definitely look at the dizzy venting thread that @OSS posted. I just dealt with that this week and gained ~15% more vacuum at idle. Like you, my truck had been running well before. But now it runs better.

So tell us, are you fully smogged? All emissions equipment intact in other words?
 
@robcgray definitely look at the dizzy venting thread that @OSS posted. I just dealt with that this week and gained ~15% more vacuum at idle. Like you, my truck had been running well before. But now it runs better.

So tell us, are you fully smogged? All emissions equipment intact in other words?
I will, thanks

I cannot be certain that all emissions equipment is in good working condition, but I believe it to be fully smogged.
 
I will, thanks

I cannot be certain that all emissions equipment is in good working condition, but I believe it to be fully smogged.
If all of the equipment is in place start going through the Emissions FSM and testing stuff system by system. I’d start with SC, AI, and EGR. The book will make it clear.
 
here is a collection of toyota documents that show the emissions routing. Also refer to the emissions manual as each emissions system is highlighted. When I replaced my old and hard vacuum hose with silicone hose a couple of decades ago, I labeled the ends of the hoses using wire markers similar to what is shown below. Either I would use the port location on the device the hose attaches to, a reference from the FSM or use the small terminal label in the booklet corresponding to the wire label used. These held up surprisingly well for 15 years or so.

If your truck is desmogged, these diagrams may not help so much. Otherwise it is not a difficult task but it does take some attention to detail.
 

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I now realize that I have been hearing cabin farts. It sounded like a speaker popping, so I thought it was just my radio. Bought 2 new VCV from city racer and installed both, routing lines as shown a couple posts above.

The diagram frrom EC manual don't do a good job showing all the connections, and unscrambling what was done to PO was a bit confusing.

Edit: attached diagram was helpful for connections to distributor and the VCV near there

Started and runs fine. Going to test drive later.

I still need to go through the other systems, by the book.

Thanks again to everyone for your input.

Screenshot_20220415-110059_Adobe Acrobat.jpg
 
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I now realize that I have been hearing cabin farts. It sounded like a speaker popping, so I thought it was just my radio. Bought 2 new VCV from city racer and installed both, routing lines as shown a couple posts above.

The diagram frrom EC manual don't do a good job showing all the connections, and unscrambling what was done to PO was a bit confusing.

Edit: attached diagram was helpful for connections to distributor and the VCV near there

Started and runs fine. Going to test drive later.

I still need to go through the other systems, by the book.

Thanks again to everyone for your input.

View attachment 2982228
That diagram is ok for figuring out some things, but at the end of the day I don't find it very helpful. Do you have the Emissions FSM yet? PM me and I can share it if you're in need. It's got much greater detail and is more exact about how exactly the vacuum lines hook up. To me the most helpful thing about undoing a PO's messy vacuum routing is to buy 40' of 3.5mm hose and 10' of 5.5mm hose and just methodically replace it all, one by one, per the FSM. It takes maybe an hour and then you know for sure that vacuum routing isn't the cause of a problem.

Glad your truck is (still) running well and that the cabin farts are hopefully gone!
 
I now realize that I have been hearing cabin farts. It sounded like a speaker popping, so I thought it was just my radio. Bought 2 new VCV from city racer and installed both, routing lines as shown a couple posts above.

The diagram frrom EC manual don't do a good job showing all the connections, and unscrambling what was done to PO was a bit confusing.

Edit: attached diagram was helpful for connections to distributor and the VCV near there

Started and runs fine. Going to test drive later.

I still need to go through the other systems, by the book.

Thanks again to everyone for your input.

View attachment 2982228
Way to get after it! As @CruiserTrash mentioned, get the FSM emissions control manual. It shows everything. It will also walk you through trouble shooting each individual part and system methodically so that you’re not wasting your time and money throwing things at it you don’t need. His suggestion on getting new vac lines and overhaul everything at once is also golden advise. You’ll be thankful once it’s done! It really isn’t that difficult once you understand how to properly read the FSM diagrams.
 
I've studied the fj60 emissions a good bit while writing the emissions computer test procedure. I really don't understand the purpose of the distributor vent VCV. Why not just run the air vent line to the air cleaner like the 3fe?
 
That diagram is ok for figuring out some things, but at the end of the day I don't find it very helpful. Do you have the Emissions FSM yet? PM me and I can share it if you're in need. It's got much greater detail and is more exact about how exactly the vacuum lines hook up. To me the most helpful thing about undoing a PO's messy vacuum routing is to buy 40' of 3.5mm hose and 10' of 5.5mm hose and just methodically replace it all, one by one, per the FSM. It takes maybe an hour and then you know for sure that vacuum routing isn't the cause of a problem.

Glad your truck is (still) running well and that the cabin farts are hopefully gone!
I do have the emissions manual. I did not see labels for the ports on the VCV, especially where the S port connects.

I also have new vacuum hose on hand that I will use first as I go through the trouble shooting steps, then, with whatever is left.

Thanks for the help/tips.
 
I've studied the fj60 emissions a good bit while writing the emissions computer test procedure. I really don't understand the purpose of the distributor vent VCV. Why not just run the air vent line to the air cleaner like the 3fe?
Toyota probably asked the same question. I’m not familiar with the 3FE so I couldn’t say for certain, but it probably doesn’t matter much either way as long as the dizzy is vented. They will explode if not vented properly. Maybe Toyota changed to the 3FE routing because the 2F was having issues with the dizzy venting properly under some circumstances. Perhaps they changed it to make things easier in the factory? I don’t know really. I just know that you don’t want gasses building up in there.
 
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I've studied the fj60 emissions a good bit while writing the emissions computer test procedure. I really don't understand the purpose of the distributor vent VCV. Why not just run the air vent line to the air cleaner like the 3fe?
From what I can tell, all the valve does is open the dizzy port to the air cleaner when the engine is running, and close it when the engine is off. Is there a reason to seal it when the truck is shut down?

My VCV was broken so I just piped my dizzy straight to the air cleaner. I've been running great, no dizzy "farts".
 
They will explode if not vented properly. Maybe Toyota changed to the 3FE routing because the 2F was having issues with the dizzy venting properly under some circumstances.

@cps432 nailed it.

The 2F’s carburetor float bowl boils out gasoline fumes after engine shut down into the air cleaner housing.
Since gasoline fumes are heavier than air, they’ll find their way to the distributor vent pipe and migrate down the vent tube into the distributor - and the next time you start the engine… explosion!

The VCV clipped under the air cleaner housing closes the vent passageway to the distributor, preventing gasoline fumes from entering the distributor after engine shut down.

Since the 3FE doesn’t have a carburetor, gasoline fumes entering the distributor isn’t possible.
 
@cps432 nailed it.

The 2F’s carburetor float bowl boils out gasoline fumes after engine shut down into the air cleaner housing.
Since gasoline fumes are heavier than air, they’ll find their way to the distributor vent pipe and migrate down the vent tube into the distributor - and the next time you start the engine… explosion!

The VCV clipped under the air cleaner housing closes the vent passageway to the distributor, preventing gasoline fumes from entering the distributor after engine shut down.

Since the 3FE doesn’t have a carburetor, gasoline fumes entering the distributor isn’t possible.
Great explanation. That would explain why - after bypassing that VCV while I await a new one - I've been smelling more occasional gasoline fumes. Fumes from carb go to the air cleaner, to the dizzy, then into the cabin via the dizzy fresh air hose.
 
Yeah I think if the distributor venting VCV is inoperable or missing, it’s better to not connect the distributor vent hose to the air cleaner. Maybe make an elevated attachment up at the air cleaner housing and attach a little air filter to the vent hose so it can breathe inside the engine bay but not into the air cleaner.
But it’s really important to keep moisture out of the distributor too.
 
That explains it, thank you. The 3fe has a check valve between the distributor and the vent filter to keep fumes out of the cabin I assume. I don't use it in the 40 since, well, you know about the fumes. The 3fe distributor will look like this if not connected to the air cleaner to get good suction through it:

1650055228429.png
 
That explains it, thank you. The 3fe has a check valve between the distributor and the vent filter to keep fumes out of the cabin I assume. I don't use it in the 40 since, well, you know about the fumes. The 3fe distributor will look like this if not connected to the air cleaner to get good suction through it:

View attachment 2982533
That’s bad. But it can get worse..
 
A lot worse-

 

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