Simann

Guys,

As with all of my other older cars I have always deleted the EGR systems and subsequently always have had better emissions results ( have them on paper for the Supra, Civics (LOL), Maxima, my brothers 300zx).

As for my 4runner, I was looking at my spark plugs that I actually just replaced yesterday with some new wires and they showed signs of a stuck open EGR system.

All this to ask if anyone knows of any company or person that makes a EGR delete for the 3 liter v6 (89-94?) 3vz? They are usually just blocking plates to cover the holes to the intake side and usually I would just use a bolt to stop up the tapped bung for the exhaust manifold.

Either way I will do something to get rid of it, the charcoal canister. Anyone who deals with military gas masks knows about charcoal canisters and how long they last at a maximum of 2 years running constant. Same with the EGR systems. They get stuck open most of the time, and in rare cases are stuck closed.

Being stuck open would induce premature spark plug wear, power loss and possibly detonation (increased intake air temperature).


-Jonathan mann

millertime_t1

i just made some for a 22re-- do u have any machinist friends?

Simann

Click on my signature

I am just testing the waters to see if anyone makes them already for the 3vz. If they dont, I could make a couple of sets quite easily.

Crymson

Quick and easy way to disable the EGR system is to disconnect the vacuum hose attached to the top of the valve and block the hose off with a plug or some tape. Voila EGR system bypassed. I just did this last week in my 3VZE and have noted an improvement in gas mileage and the flat spot between 2000-3000 rpm is gone.

Simann

Well I am doing it for asthetics and function alike.

Yes you can simply unhook the vacuum tubing but the ugly large mass of rusted tubing is still there!

But good thoughts! It occured to me yesterday, but today my brother reminded me. He has high flow cats, headers and no egr on his 300zx n/a. With those, his C02 levels and C0 levels were dramatically reduced!

The charcoal cansiter AND the cruise control are going as well. I never use cruise (I put on an aftermarket wheel anyways so its already gone), and again the charcoal canisters are LONG passed their useful life cycle.

-Jonathan

trythis

That's funny, I replaced (not removed) my stuck EGR, plugged vacuum tubes, cleaned out the egr filter and the plenum egr tube and my mileage got better, and engine ran smoother. There arent any emissions tests in Kansas, so I can't test that.

Crymson

An EGR that is stuck open will decrease your performance and gas mileage. By introduing spent exhaust gas into your manifold your are displacing the oxygen which is necessary for combustion. EGR open = less air, less air = less power. And with that lesser amount of air being introduced, the same amount of fuel is being introduced and is wasted as there isn't enough air to completely burn it, thus thats where the increase fuel economy comes from.

94SRUNNER

How would I test to see if my EGR valve is stuck open or closed? Thanks.

Crymson

Here is the diagnostic procedure from the 93 toyota factory service manual for the EGR system.

http://personal.utulsa.edu/~nathan-b...77exhaustg.pdf

GrimReaper

The control doohickey for the EGR is notorious for giving it up on Toyota's.

EGR DOES NOT HURT PERFORMANCE OR MPG WHEN PROPERLY WORKING.

When properly working the EGR is off at Idle
When under hard acceleration the EGR is off.

The only time the EGR should be open is at steady cruise. So knowing these FACTS how does it hurt performance when properly working?

Lots of people like yanking them but hardly anybody really understands how it works and if they did they would fix the thing instead of yanking it.

At steady cruise you only need about 40% of the power the motor is capable of to maintain speed.

What a EGR does is when you reach a steady cruise the fuel mixture goes lean. This reduces emissions and it reduces fuel consumption. That causes a problem in that the NOX and combustion temps start to rise. This can lead to detonation, Burned valves, Burned pistons, melted cats and other ugly things. To combat these high combustion temps the EGR opens and allows inert gas (exhaust) into the combustion chamber. This dilutes the oxygen content so it actually brings the effective fuel mixture back down to a 14.7:1 ratio. Lowers combustion temp and NOX and tendency for detonation when you hit a slight grade.

Now WHY your CO dropped without the EGR is this. You were at a lean mixture. SO yes your CO did drop but your NOX went up it just didn't go up high enough to cause a fail on the test. Now if you run the mixture fat then yes you can run without the EGR and yes you performance would indeed seem to improve because when it leans it gets back closer to an optimal 14.7:1 fuel mixture. So yes your economy would go up because you have other issues that caused your mixture to be fat in the first place. Now if everything had been working properly in the first place it would be even higher with a properly working EGR.

Also with a o2 Sensor you may actually get back to a proper mixture on older systems that do not monitor the EGR function like the newer OBDII's do. The systems were not as smart. On some of the older systems the EGR actually helped make the engine lean because when the O2 sensor see's it running rich because the EGR is reducing O2 content it will back out of the fuel and then again it results in lower fuel consumption. Just depends on how that particular system is designed.

95RunnerSR5

i plugged my vaccuum hose a little while ago and it fixed my mysterious problem of my torque converter locking up... up until now it never did lock up. i'm guessing the EGR valve is stuck open on mine because my truck runs so much better now also....funny how an exhaust component can cause a tranny not to function properly

Crymson

The EGR system hurts performance and fuel economy when it is active in my daily routine. The EGR system operates under light-moderate throttle conditions, which constitutes the entirety of my commute. During steady state cruising on highways, the EGR prevents me from maintaing speeds on uphill grades, and during passing/merging situations thus requiring a greater stimulus of the gas pedal.

That larger stimulus results in more net fuel being burned. If my commute consisted of a flat road for 20 or more miles, then I have little doubt that it would in fact improve fuel economy. The system may in fact give better fuel economy on the flat sections but that advantage is countered by the increased fuel requirement of the stoplight to stoplight driving and hill climbing.

The elimination of recirculated exhaust gas enables application of light-modest throtle to be satisfactory for most driving conditions, which for me uses less net fuel without it than with it. And the performance benefit is strictly under these light-modest throttle conditions not in racing.

As for the cylinder temp reduction benefit I have no arguement.

tampabayota

dont remove it your going to deplete the ozone layer of the atmosphere

MRunner

how exactly?

GrimReaper

Go by an exhaust shop and see if your converter is plugged. To much back pressure will cause those symptoms with the EGR. It forces to much exhaust through the EGR.

Again at the times you are accelerating from a light it should be closed. If it isn't you have a problem.

trythis

Thanks for the insight GrimReaper.
The ozone is depleted by old gasses used for propelants, and freon (r12). The vehicles (with emissions bypasses like egr, and catalytic converters removed) that polute more are causing acid rain (the reason all grave stones are granite vs marble now), smog, asthma, bronchitus, lung cancer, among other problems.

I say fix the real problems that casue your EGR system to to foul up, then watch your vehicle perform better.

Simann

Ha! Speaking of exhaust, I know my 170K mile old cat is beyond its useful life. I am going with a 3" header/collector back system (custom of course) with a 3" high flow cat.

I can put up proof that the catalytic converters (old stock) and the EGR systems that are 15 years or older should be trashed. I will take some pics of my brothers Z car, and see if I have my Supra's tests. Tennessee is not leinent (sp?) on emissions whatsoever. If we were all running ethynol (hopefully will be in 10 years) there would be ZERO emissions. Clean burning! We are actually studying this in school right now. LOL

Should free up some back pressure. I will go with a nice muffler though. I really dont want the 4runner to be as loud as my Supra was ...of course it was turbo...

Anywho, great points guys! I am actually astounded by the knowledge you guys have vs. some other forums I have been on. I guess you all dont really have the "ricers" on here. Trucks are a man's thing


-Jonathan

GrimReaper

A: I don't buy into the sky is falling. I am the wrong person to cuddle up to with your bias.

B: Fuel injected vehicle running relatively well WITH NO CAT are only a very small percentage of the problem of pollution. Your local Power company is the biggest polluter of them all and their lobbyist have rolled the blame onto the cars...yeah early on it was warranted and Lead really did need to go but 10 years ago when everything on the road was running FI it was no longer warranted.


A Cat is a patch for a poor running car. It lets people who don't do a good job of maintaining their junk go longer between needed maintenance without increasing pollution. It was shoved up our A$$ when cars had carbs that cannot be tuned as well as FI and at some point through the RPM range they run pig rich. Its the law so I don't tell people to remove them. All my cars that are required to have cats have them. My Toy passed emissions and has a cat, My wifes Honda again passes emissions just fine and has cat. My 3/4 ton 454 powered 10.5 MPG 8600lb GVWR Suburban has a cat as well...its under the work bench right next to its air pump. Its Emissions exempt because of the GVWR. Freakin POS bead converters and Air pumps are the devil. My 79 K5 had them cleaned out and passed emission's just fine with no Cats and a working EGR.

C: Electric cars charged off the grid are remote polluters and 10 time worse then a gasoline car in good running condition.

D: You really do buy into it don't you. Do some Research on R12 and R134 that isn't biased. Look when the patent ran out......isn't it amazing that just as the patent on R12 ran out that Dupont helps push it out the door because "its so bad for the environment" in favor of R134a that they still have a patent on. Guess what: that patent is about to run out too and Ohh gosh now that stuff is bad too time for the next refrigerant Dupont still has a patent on. :pat:

R12 has larger molecules. Its MUCH easier to keep in the system. R134 is so minute that a leak the lets it out readily wouldn't allow the R12 out......SO instead of having to charge your R12 vehicle every 5 -6 years you get to charge your R134a car every 2-3....SO JUST HOW IS THAT BETTER WHEN IT GETS OUT SO MUCH EASIER?

E: my issue is MONEY. I don't like spending it. I am a cheap bastard. I make sure my junk runs right because it is cheaper then fixing burnt valves. The engine and its management system was designed to run the part and short of going to a stand alone or a piggy back you can't make it run right without it and even running wet enough to eliminate detonation you are still wasting fuel ($$$).

Now if you will excuse me I need to go out and put the pan on my 400 Pontiac so I can flip it back over and get the Eddlebrock RPM bolted on and the Demon 750 (the biggest fuel eater next to the predator) on it and back in the car and destroy the ozone some with Frying tires.

GrimReaper

Yeah see if you can find the tests. I bet when they are reviewed the NOX will be just shy of failing. You have a APEXI on it or anything else to lie to the ECM?

I use to roll with the Surpa crowd here in Atlanta when I had my 89. Nightmare (of www.supracentral.com) is a buddy. Miss that car. It was fun. Just didn't think it could handle the 22ft Airstream we inherited when my Father-in-law passed so I sold it to get a Burb to move the camper.

I am with you on the Cat. Bead style are crap. The Monos especially the toy ones are pretty good and as long as some run problem along the way didn't screw it up they usually make the long haul. EGR other then that control solenoid Toyota uses are simple and there really isn't anything that cant be fixed on them easily so I don't see eye to eye with you on them.

If I didn't have to deal with the ATF there would be a still going in my backyard right now making stiff drinks for the fleet.

Simann

Now lets not turn this into an Ecological disaster thread. LOL

Larger power stations and such are the largest polluters.

Electric cars are worse. Think of the HEAT radiated from the power cells! Do you know what EMT's and HAZMAT crews have to do when there is a car accident including a HYBRID or a Electric car? I have actually been in the operating room when a EMT was ELECTRICUTED by a hybrid at the scene of an accident! He had some SERIOUS burns on his hands. Also the battery cells if ruptured have some nice chemicals as well!

Either way, you can make a car pass emissions withou cat's. I have done it, but obviously failed the visual inspection.

Biodeisel and Ethynol are the fuels of the future. They burn ULTRA clean (virtually zero hydrocarbons) and they still give us the thrill of the internal combustion engine! (relibility and safety and also ease of maintence, something hybrids are going to struggle with 10 years from now).

I will love it when fuel injector companies will start selling aftermarket injectors and fuel lines to retrofit our older vehicles to run Ethynol, or at least a BLEND.

-Jonathan