83

The "experts" seem to think that removing the EGR will increase combustion temps. In theory this makes the engine run hotter, and in theory you should get slightly worse gas mileage. But I don't think that there is hard data showing that this is actually the case. I think that in practice, if there is a difference, you won't notice it. Like Pumpkinyota touched on, a malfunctioning EGR (or any part of the emissions system, really) will have a much more noticeable and negative effect on your truck's performance.

I think the fact that all vehicles now have EGR says something. When it's functioning properly, it does help. But they're just so prone to clogging...if you don't need one for emissions testing, or you aren't one of those people who just wants the truck to run as clean as possible the way Toyota made it...then you're probably better off without the EGR.

Off the top of my head I don't see why removing all this stuff would effect off camber driving..

95yoda

I know I dont have that massive belt driven smog pump on mine ill have to check for the egr. I do have a few hoses on the pass. side fender but nothing like that pic shows.

streetlancer

iTrader: (1)

What if i don't have this valve? I have air injection but the valve looks completely different; it looks more like a rectangular box.

Pumpkinyota

That would be a reed valve. The one shown in the picture is a PAIR valve. For the purpose of this discussion, they are functionally similar enough to be treated as the same, they have the same basic purpose. The main purpose of the pics of the PAIR valve are to show you the physical location, and the location of the mounting hardware, which should be the same for either a reed valve or a pair valve.

Robs Toynado

Very nice Pumpkinyota, This was a real nugget of info!! Nice work keep it up!!

yota81

thank you very much. this was much needed.

Pumpkinyota

Glad it's helpful! I will have more info up on the carbeuration side of things soon, hopefully later on tonight.

yota81

when you're done, i'm all over this. I got vacuum leaks everywhere.

chrisj345

So, I am new to the 83' yota and have just a little question for this thread.

I still have a EGR valve on the truck but I only have one belt. Mine has an air injected manifold, but it is removed and one of the holes is open.

Should I stop running the truck until I get it closed up?

I have access to another 22r with any engine parts.

Should I close up the hole, or should I put the original stuff back
on?

Pumpkinyota

WELLLLLLLLLLLL........

I can't legally answer that question completely. Federal law says that you have to have an EGR valve installed and working if you want to operate on the highway.

That being said, unless you are somewhere where smog restrictions are highly enforced, it is unlikely that anything bad would happen, if, hypothetically, you de-smogged the truck. About the worst that would happen is that you would get a fix-it ticket if you pissed off a cop real good.

Now, also hypothetically, from an off-road only standpoint, an EGR valve is just another complicated piece of equipment to break and cause you problems. In this case, from a performance and expense standpoint, you should make sure both of those Air Injection ports on the exhaust manifold are blocked off, and the EGR will be non-functional.

Have you noticed a MASSIVE exhaust leak? Because that is what you should have with one of those ports open...

Pumpkinyota

Thread continues now:

To Recap, so far we have:

Removed EGR valve

Removed Smog Pump

Removed PAIR or REED valve

Removed Vacuum Manifold

Removed Air Injection Manifold

Blocked off Air Injection ports



Our next step is to block off the holes where the EGR used to live. Hopefully you have already either ordered and recieved block plates from here:

http://www.lceperformance.com/Block-Plates-s/1447.htm

EDIT - LINK UPDATED to correct broken link.

OR, if you are motivated, and have the tools, you can make your own block plates by tracing the outline of the EGR and EGR output tube onto some 1/8" steel plate, and cutting them out.


Here are what this will look like when done:

EGR block plate at the head:


EGR block plate at the Intake:

chrisj345

By exhaust leak do you mean a fluid?

There are no fluid leaks what so ever from the truck. I thought that was great from the beginning.

So running it now is not going to hurt the truck? If I run it without doing either will the engine be injured?

Pumpkinyota

No, by exhaust leak, I mean a leak of exhaust. As in, clouds of exhaust billowing out of the open port in your exhaust manifold.

The engine probably won't be injured, although with an exhaust leak that size, you may introduce too much heat into your engine compartment, causing higher than average temp.

The easiest thing to do is just to block that Air Injection port. You can fab up a few plates yourself, or buy a kit from LCE for like 20$ shipped.

chrisj345

I will stop being that guy who messes with the thread.

I am just realizing that my truck has been about 1/2 de-smogged. I look forward to seeing the full process.

Thanks so much for the thread.

And, YES. there is an extreme exhaust leak!

Pumpkinyota

No prob, the whole point of this thread is to help out, ask all the questions you want. Once this is mature, I will probably roll it into a tech writeup, and clean it up anyways.

Actually, your truck has no real functioning smog equipment anymore. Finishing the rest of this will probably make it run better and cleaner...

There would almost have to be an extreme exhaust leak. That Air Injection port on the exhaust manifold is just a port straight into the manifold, you are basically venting exhaust straight out of it with no obstruction.

chrisj345

So why would these two hoses be blocked? you still have those going somewhere.

Also, in the state shown below, do you feel like the carb system might have something to do with my stalling problem? It basically acted as if it was running out of gas. the thread is "83 Pickup Idle and Stall Problem."

Those springs on the throttle really bother me and I don't understand why they were put there by the previous owner.

I think I will prob keep following the thread and consider doing this, but will the fact that I am missing those tubes hurt?

springandblockedhoses.jpg?t=1268195890

Pumpkinyota

Now, we are finally on to vacuum!

Thanks to Blue Bass Design for putting this info online.

Here are the important bits:

AAP - Copied verbatim from the Blue Bass site:

"All the AAP does is squirt a little extra fuel into the mixture when the engine is cold. It has no effect on the engine when warm - even when not working properly. The AAP is vacuum operated - when vacuum is applied the diaphragm opens which then adds a little extra fuel. The vacuum is applied by the BVSV which is screwed into a water jacket on the head. This senses the temperature of the coolant and applies or does not apply vacuum to the AAP."



BVSV - The BVSV is a vacuum switch that is controlled by engine temp. Think of it like the thermostat in your house: when the temperature gets to a certain point, the switch opens or closes. In the case of the BVSV, it is open by default, and closes when the engine temp warms up. Vacuum is applied to one side of the BVSV at all times, and the BVSV applies vacuum to the AAP and/or Choke Opener diaphragm when the engine is cold, allowing these to operate. Once the engine warms up, the BVSV closes, disabling the AAP and choke opener diaphragm.

BVSV Pics:





Choke Opener Diaphragm -
Again, pics and text copied verbatim from Blue Bass Design...

"This diaphragm slowly disengages the fast idle cam which in turn opens the passenger side choke plate. The choke opener, like the AAP, is also controlled by vacum from the BVSV. This diaphragm is not necessary as you can acomplish the same exact thing by punching the gas pedal when you wish to disengaged the fast idle cam."




High Altitude Compensator -
Some of these trucks have a High Altitude Compensator installed, although yours might not. Here is what it looks like:






Distributor Vacuum Advance -
This changes the distributor timing curve based on the RPM of the engine. We could spend a LOT of time discussing the reasons behind this, but as this is a de-smog thread, not a basic mechanical thread, we won't give much detail here.




Charcoal Canister -

Verbatim from Blue Bass:
"The charcoal canister(s)'s job is to vent the gas tank. Basically the worst that will happen if they are clogged is when your tank gets near empty and you undo the gas cap, you will hear a whoosh of air go into the tank. This is because a vacuum is created in the tank as gas leaves and no air can enter through the canister due to it being clogged. You can usually blow the canister(s) out with air to unclog them."

Pumpkinyota

The vacuum ports that you have circled there are for the high altitude compensator. As you don't have one installed, having them blocked off is correct.


The spring shown is a redneck'ed in replacement for the throttle return spring. It probably isn't hurting anything, but you can get a much better spring at your local hardware store for a couple bucks.

Pumpkinyota

You can add or remove many of these features and functionalities, depending on how you operate your vehicle, how simple you want it to be, how well you want it to cold-start, etc.

Here is the base minimum:

Remove all vacuum lines from your carb. Install the following:

Distributor vacuum advance:


Port 1, in yellow, to port 1, in yellow, in the following pic. The same for port 2, in green. Keep in mind, these pics are to show you the location of the vacuum ports, mine is set up to include the HAC, so the actual vacuum lines between will take a slightly different path.




Install a vacuum line from the carb to the charcoal cannister (#1, in yellow). Make sure that the fuel return line is installed (#2, in green).



Cap every other vacuum line off, and you can roll just like that.



And, now I am having connection issues with YotaTech, so we will have to continue this later. Coming soon though, my attempt at a well balanced setup.

seagullplayer

Great post!

I just checked under my hood, I still have an EGR valve inplace.

My question, if I remove the valve and the tube, then make a blocking plate out of something thin, like a pop can, then put everything back together with the blocking shim in place, will this give me the same result as if I removed everything from the truck?

Thanks