Blocking EGR

[SWR Banned Find all posts View Profile Close SWR]

Hi Guys

I will try to explain the principal of the EGR on the 1KD-D4D (Not the 1KZ) best i can based on my understanding and why i believe you can "not" restrict or block the EGR due to its complexity and impact it may have on the variable turbo!...

A detailed difference of opinion is most certainly welcome from a progressive point of view as i may have missed something and it doesn't help the fact that i did not build/ program or map the system so i believe a problem shared is a problem halfed!.. (Healthy debate gets results!).

I will start from the air filter box towards the engine as follows!

#1 MAF: (Mass Air Flow) meter that measures air flow and mass (altitude/atmospheric) via a hot wire! (wire is heated to a specific and the voltage is add/reduced to keep its specific) ECU then works out air flow & volume based on current. (It pays to keep it clean from contaminants).

#2 VARIABLE TURBO: (Variable Geometry) also has the ability to increase exhaust back-pressure on cruise and mid range to increase EGR flow to the engine as well as increase turbo boost right across the RPM (Revs Per Minute). I believe (Looking at the wiring diagram for Australian model) there is also a sensor implemented on the actual turbo to monitor turbo spooling. (to provide the ECU of the turbines RPM so it can control boost and stop over spooling).

#3 PCV: (Positive Crankcase Ventilation) drawn into the negative side of the turbo compressor to be re-burnt via the induction process to reduce emissions being vented to atmosphere (Closed loop PCV). This is also where the oil mist condenses back to its oil-form when being cooled via the turbo inter-cooler. Hence oil residue build-up in the intake manifold components and then made into a black sticky substance when the EGR gases are drawn across the oil residue!

#4 TURBO INTER-COOLER: is used to cool and condense air mass before being drawn/pushed into the intake manifold (Is where the PCV vapor converts back into oil form).

#5 AIR TEMP SENSOR: located before intake manifold (Based on its temperature) can measure air density calculated by the ECU.

#6 MAP: (Manifold Absolute Pressure) to monitor manifold intake manifold pressure. (Hose is connected ahead of the venturi-flap & EGR valve to monitor accurate intake pressures).

#7 INDUCTION SWIRL FLAPS: In a typical 1KD-D4D (Not the 1KZ) they have Swirl flap implementation and the flaps will be closed at idle speed (Located inside the intake manifold (8 x ports reduced to x 4) and controlled by two electronic vacuum solenoids which is controlled by the ECU based on its various engine sensor input signals), creating additional turbulence in the intake (Combustion chamber)...

As engine speed increases, the flaps are gradually opened until they are parallel to the airflow and present virtually no resistance. Their purpose is to ensure that the air entering the cylinder is sufficiently turbulent for good fuel-air mixing even at low engine speeds. This aids in reducing certain toxic emissions and may also improve low-end power and torque.

If Swirl Flaps stick in open position: Deterioration in exhaust gas characteristics in lower speed ranges otherwise no effect.
If Swirl Flaps stick in closed position: Power loss of approx. 10% at higher engine speeds.

#8 EGR (Exhaust Gas Recirculation) heat exchange to cool the inert gases before being forwarded to the EGR-valve.

#9 INTAKE VENTURI FLAP: used to help increase negative manifold pressure (Motorised flap controlled by the ECU based on numerous sensor feed-back data) to increase EGR flow and also slams shut on engine shut-down to help give smooth engine shut-down.

#10 EGR (Exhaust Gas Recirculation) valve to supply inert gases into the combustion chamber to help suppress peak-duration high temps and is situated after the variable venturi flap so that the intake manifold negative pressures can be increased when summond by the ECU based on its sensor-input signals.

I will not include all of in-put sensors as i want to focus mainly on the EGR without trying to explain the full engine cycle whilst cruising etc.

CONCLUSION: The variable veins close on the turbo based on the data sent to the ECU from numerous engine sensors. The turbo speeds-up/ Exhaust back-pressure increases/ In-take venturi semi closes/ Negative manifold pressure increases/ EGR valve opens/ ECU's calculated air+inert exhaust gases are drawn into combustion chamber with the correct fuel ratio accordingly via the fuel injectors (ECU is watching manifold press+rpm, Swirl-flaps react accordingly to data inputs.

peak-duration temps are now kept under control with the injector pulse and duration for fuel accordingly to RPM & engine load!

Now with Nox under control the Diesel oxidation catalyst (DOC) will take care of the other nasty gases before being discharged via the tail pipe... A DPF (Diesel Particulate Filter) may also be employed to catch the soot particles.... I say maybe as am not up to date on the 150 series!

ALSO! lets not forget the Induction/ Combustion/ Power/ Exhaust! (Suck-Squeese-Bang-Blow with 2 x full crank revolutions for one fire cycle)...

WHY? Because a compressor sucks and blows air only! (Same volume-in/ same volume-out!... Engine also De-cellerates as a vacuum is developed instead of a power stroke which is normally produced by expanding fuel/air.

When the engine is in its power cycle (4 x Cyl) it sucks but also draws fuel with the air... This air/fuel expands when ignited so the exhaust pulse now has a much more mass/heat with a driving energy which would equate to bigger mass out-put compared to a normal air compressor!... From a puff of air to a bang of hot high energy!

This is important to note because an engine that is giving power has a higher pressure force on the exhaust up-stream from the turbo... If no fuel is applied then the exhaust pressure will drop. This is important if you want access inlet manifold boost to push past exhaust pressure.

All a-side! I now De-press the Accelerator pedal/ Variable turbo veins closes/ Variable venturi opens/ Fuel supply is reduced (Fuel Injectors close), Power induction drops/ Exhaust pressure on the turbine compressor also drops as the engine is no-longer producing power!...

Now at this point i believe (No hard proof) before the EGR-valve closes the access boost is dumped via the EGR as the intake manifold press would still be initially higher than the exhaust gases due to a spooling turbo that is still producing pressure and because the fuel has now been removed from the power stroke (4 x cyl) the energy that was coming out of the exhaust port would now be lower than the in-take manifold so i believe the greater in-take mass can now purge back through the exhaust port accross the turbo, then when the main boost surge has been dumped the engine can naturally consume the small residual pressure from the still spooling turbo! (Suck-Squeez-Vacuum-Push due to 2 x crank revs for 1 x cycle).

I believe that when the engine is under constant high load with high boost the ECU will reduce the pitch of the variable veins (Close) to reduce or drop the boost pressure (Slow down the turbine RPM).

EG: open the turbines variable veins fully to increase turbo RPM spooling and close the variable veins to reduce turbo RPM if turbo over-spools or boost rises too high.

Do not forget that the ECU works out the fuel/Air ratio with the inert gases added to the equation on cruise and mid range and the engines life span is mostly cruise and mid-range on average!

When you have the pedal to the metal (So to speak) the Air/Fuel ratio will be calculated without inert Exhaust gases in the air/fuel equation!... I believe if all sensors are giving true values to the ECU and the engine is under high-load and reving hard for a long period duration the engines factory mapped perimeters will step in and save the day so-to speak.

I did notice a distinctive drop of engine performance under cruise/ mid-range and a nosier turbo when i personally messed with the EGR on my rig.. I posted these observations nearly 12 months ago at the beginning of this thread.

Cheers

[winniliss Avid PP Poster! Find all posts View Profile Close winniliss]

You're the man Harry

[Chip It Senior Member Find all posts View Profile Close Chip It]

Hi SWR

Good post. I wish I had the time to post detailed posts like that. Truly, my hat is off to you.

Couple of points:

In the part where you say "All a side", you may wish to change the word "De press" as I think, in reading, you mean reducing throttle input. The rest of the paragraph would them make sense. "Depress" would be read to mean press your foot down on the accelerator and then the paragraph would read wrong.

On another point, regarding our long debate.

Have you ever measured the pressure in the intake with the EGR blanked off? even with it blanked off there is NO pressure increase when you back off. You can back off as fast as u like ... u cannot get an increase in pressure build up. The rotating of engine with intake valves still open allow the full escape of the turbo pressure.

Also, may I ask you to measure for negative pressure in the intake at ANY regime? In a diesel, even the modern diesel there is always positive pressure. The MAP sensor is never measuring neg pressure. With the throttle valve almost fully closed and the EGR open the pressure in the intake manifold is around 2 - 4 psi. This is direct pressure from the exhaust manifold. ie this pressure would normally be used to drive the turbo impeller but now it is ported off to feed the intake which is "available" since it is at a lower pressure than the exhausted air. When you blank the EGR the ECU throws a wobbly because it is no longer getting the 2 - 4 psi needed to keep the it happy. Case in point: if you allow turbo boost to get past the butterfly (I have my throttle plate drilled with a 12mm hole) (other methods we have used is to run a hose from upstream of the butterfly Tee pieced into the MAP sense port) the ECU no longer throws a CEL.

[Chip It Senior Member Find all posts View Profile Close Chip It]

BTW interesting article here

http://www.newtriton.net/phpbb/viewt...rl+control+mod

People are deleting the swirl valves and getting positive results arbitrarily.

I think you need an account to view

[SWR Banned Find all posts View Profile Close SWR]

Gday chipIt

Thanks for the corrections on a couple of points... Much appriciated!

Just a few questions i am curious about!

Quote ChipIt: With the throttle valve almost fully closed and the EGR open the pressure in the intake manifold is around 2 - 4 psi. This is direct pressure from the exhaust manifold.

Question skywalkerrun: At this point would it be fair to say the ECU has calibrated the correct fuel/Oxygen + inert EGR ratio with the intent to surpress peak duration temps?..... I thought the engine only run on approx 15-30% EGR? Where did the oxygen go in that equation and if the turbo has built-up 4psi back-pressure how much boost is sitting in the intercooler given that the EGR only opens on cruise/mid-range? (Usually about approx 2 to 2,500 rpm). Depending on MAP feed-back!

Quote ChipIt: When you blank the EGR the ECU throws a wobbly because it is no longer getting the 2 - 4 psi needed to keep the it happy.

Question skywalkerrun: When the ECU throws a wobbly what was the fault code or codes?....

Quote ChipIt: Case in point: if you allow turbo boost to get past the butterfly (I have my throttle plate drilled with a 12mm hole) (other methods we have used is to run a hose from upstream of the butterfly Tee pieced into the MAP sense port) the ECU no longer throws a CEL.

Question skywalkerrun: Was all these methods performed on the 1KD-D4D?..... It all sounds random stuff!!... Isn't the MAP sensor already plumbed up-stream of the butterfly (1KD-D4D) and where do you connect the other end of the hose when you tee'd into it?... When you say! Quote chipit: "Other methods we have used" Un-quote. Which method do you actually use and do they actually work successfully on the 1KD-D4D?

Also! given that the butterfly drilled/ EGR blocked would the fuel ratio's now be up the creek given that the MAF readings would now be altered and have you pulled all the above off successfully on the 1KD-D4D?

Cheers

PS not looked at the link on the triton site yet.

[Chip It Senior Member Find all posts View Profile Close Chip It]

We need to remember the EGR system is there to quench the temps and reduce NOx at cruise. It is not there to help save fuel. The ECU is not reducing fuel flow (this can be confirmed by watching injector PW on an oscilloscope. The fuel is still needed to turn the engine over at a desired (driver induced) torque setting. It is this fuel that gives the EGR the pressure needed to head into the ait intake. Of course less fuel would mean less turbo pressure too.

You cannot have fuel heading into the combustion chamber to give the desired power increase without the turbo spooling. The spooling creates a positive pressure but the manufacturer does not want this pressure to overcome the EGR so they blank it off via throttle valve. The turbo pressure is just kept at bay (measurable by boost gauge BEFORE the throttle valve. Again remember that pressure seen by the ECU is downstream of the throttle valve (at the MAP sensor) is MOSTLY EGR pressure. You can prove this by blanking the EGR and noting the pressure at the MAP sensor. Whereby right at that stage the CEL will come on since the MAP sensor should be reading around 4psi (from EGR, not fresh air from the turbo)

Only a very small amount of turbo pressure is let into the manifold (and to the MAP sensor) from the turbo. But is precisely this FRESH AIR that we want to be available for efficient combustion. Efficient combustion means HOTTER burning. Hotter burning produces NOx. This is where the manufacturer is being tested for reduced emissions. So they have a problem. They flood the combustion chamber with Exhaust to snuff out the flame somewhat (remember the diesel engine works on the principle of auxillery air. Meaning the oxygen has not completely been consumed during combustion... unlike the petrol engine where it is almost 100% consumed.) This extra air is in the exhaust so it does burn "again". But the less oxygen gives the manufacturer less temp and gives the manufacturer a TICK from the Euro Drive Cycle Test. IE they get to sell the engine in that country.

At WOT the EGR is CLOSED Why? Because the emission test is not conducted at WOT and the manufacture is given the "permission" to produce AS HOT AN COMBUSTION TEMP/POWER AS THEY WANT. (not angry here... just trying to make the point that if EGR System was there to cool combustion for engine safety, the manufacturer is closing the EGR System right at the time it is needed the most when the EGT's are MUCH hotter than at cruise (when the EGR System is open)

The manufacturer is NOT allowed to dump (vent) the turbo pressure externally so they just allow the turbo to suffer in silence. (and are not concerned so it seems. When the EGR System (emission test) is closed, the throttle valve is allowed to open fully and the pressure to the MAP sensor (and combustion chamber) is taken over by the fresh air pressure of the turbo.

Speaking purely from a performance perspective, we want the engine to burn with clean, fresh air ALL THE TIME. We don't want the EGR to flood the combustion chamber with oxygen depleted air AT ALL.

Having 100% fresh filtered air (from the and intake and turbo) produces MORE fuel efficiency (but would fail the emissions test so you don't get it have it)

Again, speaking purely from a performance viewpoint ... BUGGER THE EMISSIONS! Give me power/efficiency.

By drilling the throttle plate with 12mm hole and FULLY blanking the EGR, this is what we achieve. And the MAP sensor doesn't know it is measuring fresh air pressure rather than the engine's own crap, ie EGR, pressure.

In this Skywalkerrun, the EGR is there ONLY as a emissions control system. Not an engine protectant and not there to relieve the turbo from back pressure wave IMHO.

One rotation of the crank shaft with the intake valve open will certainly and quickly reduce the turbo pressure so that it does not cause this backward pressure wave. (not on a petrol engine but on a diesel) Also, as I recall on our modern diesel that at snap close throttle the throttle valve is closed so any build up of pressure CANNOT escape through the EGR. (EGR port is downstream from the throttle valve)

Your second question: The fault code is insufficient manifold pressure at cruise. Not insufficient turbo pressure but EGR. And to make it harder to defeat, the blighters at Toyota have placed a pressure switch in the EGR System to monitor EGR pressure. So you get another fault code being thrown up when you blank it completely for low EGR flow. No other car that I know of (out of all the garden variety cars in Australia) has this additional sensor. (garden variety as in normal Jap cars. I happen to love the D4D 4 and V8 engines from Toyota)

by drilling the manifold (this is just the way I do it) I give the MAP sensor and EGR pressure switch the pressure they require to remain fault free.

Q3. they fuel now is being burnt "properly" giving more efficiency and giving the driver more fuel economy.

(Dont be under the illusion anybody that the manufacturer is trying its darnedest to give you THE MOST fuel economy. First and foremost is ---- PASS EMISSION TEST --- SELL ENGINES.

Yeah take a look at the triton site ... Makes interesting reading. I learnt a lot from someone else's play time

Hope this helps

[SWR Banned Find all posts View Profile Close SWR]

Gday chipit

Good post. I see you also have the time to do a detailed post and i myself am only active on one forum!.... This one!

Chipit Quote: We need to remember the EGR system is there to quench the temps and reduce NOx at cruise.

Answer skywalkerrun: Yes it is and like you said your self "EGR system is there to quench the temps and reduce NOx at cruise.....So is it cooling or not?

Quote ChipIt: Speaking purely from a performance perspective, we want the engine to burn with clean, fresh air ALL THE TIME. We don't want the EGR to flood the combustion chamber with oxygen depleted air AT ALL.

Answer skywalkerrun: What you want and what the EPA (Environmental Protection Agency) dictates to the car manufacturers (Who in-turn invest "Millions of dollars" to achieve cleaner more efficient engines) which is heavily influenced and set in presidence by the ARB (Air Resources Board) then it is enforced by the world governments which over-rides your-say!... If you have "fresh air ALL THE TIME" then cruise temps/Nox will rise and all those "Billions" of dollars globally spent in R&D (Research & Development) have been wasted and the vehicle thrown back into the dark ages!

If temps are reduced and the engine is running within mapped (Programmed) perimeters then the engine is clearly running more fuel efficient/cooler mid-range and cruise... Most cars run 70 - 80% at cruise/ Mid-range!

I can not deny that EGR does reduce "Small" power efficiency but with the implementation of newer technology the cleaner burning/more powerful & better fuel consumption over compensates the latter... A nice re-assurance for the next generation to have a much less toxic air emission environment.

ALSO: by the time you have blocked the EGR with all the other mods you have to consider the actual benefits verses "stock" and all the manipulations to fool the ECU in-order to keep the intake clean and possibly 5% increase in power with the loss of fuel consumption as the reaction of your action i think i would personally go for the Oil-Catch-Can as appose to the latter to keep the induction cleaner!

EG: I have 2 x engines!.. Both are 4 x cylinders, Both are diesel, Both have a turbo, and both have the same cubic capacity!..... One gives more power, Better fuel consumption and cleaner burning.... For this example i will choose the 1KZ Vs 1KD.

The 1KD engine produces more power with less fuel consumption and cleaner emissions than its predecessor, the 1KZ.

1KD-FTV 3.0 L (2982cc), 4 cyl Turbo Diesel (D-4D] 127 kW (173 PS; 170 hp) and 410 N·m (300 lb·ft) of torque.

1KZ-TE 3.0 L (2982cc), 4 cyl Turbo diesel engine 97 kW (131 PS; 130 hp) and 287 N·m (211 lb·ft) of torque.

Here is a break-down on basic "FACTS" for the "APPARENT" irrelevance of the EGR & exhaust emissions.

NITROGEN (N2) Elemental nitrogen is a colorless, odorless, tasteless, and mostly inert diatomic gas at standard conditions, constituting 78.09% by volume of Earth's atmosphere.

WATER VAPOR (H2O). About 70 percent of the Earth's surface is water-covered, and the oceans hold about 96.5 percent of all Earth's water.

CARBON DIOXIDE (CO2) Concentrations of 7% to 10% may cause suffocation, manifesting as dizziness, headache, visual and hearing dysfunction, and unconsciousness within a few minutes to an hour. http://upload.wikimedia.org/wikipedi...e_toxicity.svg

CARBON MONOXIDE (CO) colorless, odorless, and tasteless. mild acute poisoning include lightheadedness, confusion, headaches, vertigo, and flu-like effects; larger exposures can lead to significant toxicity of the central nervous system and heart, and even death.

NITROGEN OXIDE (NOx) aggravate asthmatic conditions, react with the oxygen in the air to produce ozone, which is also an irritant and eventually form nitric acid when dissolved in water... (Acid rain is good at killing food crops and soil fertility).

OZONE (O3) a pale blue gas that condenses at progressively cryogenic temperatures to a dark blue liquid and finally a violet-black solid

Ambient air contains 21% oxygen, 78% nitrogen and 1% trace gases (which includes about 0.04% carbon dioxide).

first introduction of EGR was in 1972 (Was primitive in function & caused many issues back then) - Generally 5% to 15% of the exhaust gases was fed back in spark ignited engines. In diesel engines, the exhaust gases are cooled before they are fed back to the engine and much more effective by today's technology.

"FACT" - There were also 16.4 million motor vehicles, including Motor cycles, registered in Australia for the 2011 Motor Vehicle Census... That is allot of smog (Brown haze that hovers over condensed city's etc). "IF" all EGR systems are badly maintained or deleted how much worse would it be?

Extracts from this conclusion.... "Note" it was Printed "back" in June 2004 and i do believe there has been some technological advancements since then!
http://www.ias.ac.in/sadhana/Pdf2004Jun/Pe1131.pdf

One simple way of reducing the NOx emission of a diesel engine is by late injection of fuel into the combustion chamber. This technique is effective but increases fuel consumption by 10-15%, (Also produces very high particles - black soot and toxic emissions).

Three popular explanations for the effect of EGR on NOx reduction are #1 increased ignition delay, #2 increased heat capacity and dilution of the "intake" #3 charged with inert gases.

The ignition delay hypothesis asserts that because EGR causes an increase in ignition delay, it has the same effect as retarding the injection timing.

Update on EGR and emission technology are as follows!

#1 Diesel oxidation catalyst (DOC) technology is extensively used to control CO and HC emissions from diesel engines.

#2 Diesel Particulate Filter (DPF).

#3 continuously regenerating trap (CRT) systems.

#4 continuously regenerating trap systems with a catalyzed DPF (CCRT)

#5 selective catalyst reduction (SCR) systems

#6 partial filter (PF) systems

Despite that a lot of the new Exhaust technology is for big trucks (Euro 5 & 6) you will soon be seeing some of this new technology being passed onto smaller diesels.

This is an interesting read!..... Copy and paste part numbers into Google search to identify products in question.
http://www.fordforums.com.au/showthread.php?t=11358657

Watch the video (Clearing California Skies Video) on the link below and you will understand why emissions are enforced!

Introduction to the California Air Resources Board (ARB) Also known in the industry as C.A.R.B
http://www.arb.ca.gov/html/aboutarb.htm

Here is what Australia has coming as far as emissions go!
http://www.dieselnet.com/standards/au/#my02

Here is what is happening to date!
http://www.fcai.com.au/news/all/all/...-co2-emissions

Quote Chipit: (Dont be under the illusion anybody that the manufacturer is trying its darnedest to give you THE MOST fuel economy. First and foremost is ---- PASS EMISSION TEST --- SELL ENGINES.

Answer skywalkerrun: There is no illusion about the fuel economy?... "However"... There "IS" an illusion about chips giving better fuel econmy!... Any diesel mechanics wish to hop on an explain WHY!!

I believe that when the average Joe-blogs is tinkering with there vehicle that they are not aware of how much technology is under the bonnet and why things run/ happen the way they do!.. Having the information made available helps joe-blogs make a more calculated decision based on what they know as appose to what they do not know and are being told!

I am not telling people what is right or wrong but just showing facts!

Cheers

[Chip It Senior Member Find all posts View Profile Close Chip It]

Did you see what time I wrote that post? It was at 5.30AM when I posted. I started at 4.45AM.

I really don't have time to write heaps so I will be short.

The EGR IS there too cool but not too cool the engine because it might be too hot for normal operation. IT IS ONLY THERE FOR EMISSIONS. Closed at wide open throttle when the engine is hottest.

In fact, SWR please call me on 0412 304030 so we can discuss over the phone. Much easier for me to discuss back and forth at one time.

Hope you understand this will be more efficient use of time. Just have your post so you can go through it point by point.

Noted that chipping is not for everyone. But those that do Chip their vehicles may not be putting as much weight on the pollution side of things as you do. More power = more exhaust. That's a given.

But that does not stop the hundreds of thousands of users out there that are changing the way their vehicles make power: ie chips, 3" exhausts, sports air filters, larger tyres, fuel additives, etc etc and therefore changing the emissions from the standard engine that was passed to enter the counrty.

Besides which, I guarantee NO engine over 10,000 kms old will pass the emission test that it passed when the manufacturer had it on the test bench for the Euro Drive Cycle Test. None period.

If people really want to save the planet ... buy a bicycle, as the internal combustion engine is producing more emissions than anything else on the planet. Not to mention the pollution created to make the total vehicle in the first place.

BTW. As a side note: I wonder how many people on this forum are PRO the Carbon Tax which wont save a single gram of Carbon since manufacturers will offset their costs with carbon credits purchased from India and China.

Cheers

RR

[SWR Banned Find all posts View Profile Close SWR]

Hi guys

Sticking to EGR and not including any performance enhancing medicinall's! (Too many variables)...

Note: ECU (Engine Control Unit) or ECM (Engine Control Module) <<< Not aftermarket! are basically the brains of the vehicle that reads (Relies on) feed-back data from a multitude of sensors on and around the engine then interpreting the data using multidimensional performance maps (called Look-up tables), and then adjusting the engine actuators accordingly... (OEM Engine Mapped Perimeters that throw either a CEL (Check Engine Light) or MIL (Malfunction Indicator Lamp) if mapped targets are not met!)...

If EGR is blocked/restricted and the butterfly plate drilled (1KD-D4D not 1KZ) to compensate EGR pressure loss then the ECU recognises the increased air flow at the MAF (Mass Air Flow) sensor.

Note: The MAF has two wires. One is a hot wire(Kept to a specific temp and current variable equated by the ECU) the other is a thermistor wire (So hot wire knows temp to maintain) to work out air volume/Mass and Both together work out air flow. (Altitude and Atmospheric) then air density is confirmed by the temp sensor on the turbo inter-cooler.

(A reaction from removing exhaust pressure) based on original mapped perimeter targets that are needed (Supposed) to be met!...

The ECU recognises the increase in air flow at the MAF (Mass Air Flow) inline with the MAP (Manifold Absolute Pressure) readings but also looks at throttle pedal position/Engine RPM etc and at this point i believe the ECU's mapped perimeter targets are not being met so it closes the variable veins on the turbo to try and increase EGR (Exhaust Gas Recirculation)... (Increase exhaust manifold pressure to promote EGR gas flow).

Variable veins on the turbo closes and the ECU knows this as the variable turbo has a position sensor on it...

At this point i believe the exhaust manifold pressure has increased and the ECU is now throwing a wobbly because the turbo viens are fully closed (Trying to increase EGR flow & probably a noisey turbo at this point!) and should not be closed according to factory mapped perimeters so it then throws maybe a P0299 which according to DENSO mean's "VNT Closed Abnormality" = (Variable Nossil Turbo)... Also possibly a P0401 which is referred to as "insufficient EGR flow"... I also believe that the ECU would maybe also notice that the butterfly flap is fully closed (Trying to draw EGR by increasing in-take neg pressure based on the fact that the MAF flow is too high) and if so that would be a P0488 "EGR Throttle Motor System Abnormality".

A P0069 is a Pressure Difference Abnormality Between Boost Pressure (MAP) and Atmospheric Pressure (MAF).

I suppose the best way to settle this debate is for some guys with 1KD-D4D's (Guinea pigs or beta testers ) to drill the butterfly/ block the EGR and take note of there findings!

I'm guessing hotter cruise temps (No longer being suppressed by inert gases)/ nosier turbo (Higher boost pressures stalling turbo)/ Higher boost pressures(VNT trying to increase EGR)/ more engine rattle (Due to lack of inert gases retarding combustion timing delay)/ Higher fuel consumption and a noticed flat-spot whilst driving mid-range/cruise!

I am also guessing whilst all this is going on there would also be an increase in crank-case pressures.

I believe that if you was to by-pass the swirl flaps (Some how?) it would impact on the combustion swirl turbulence and promote hot spots in the combustion chamber (and not paying attention to the un-burned fuel and increased particle matter).

If all goes well then that's your choice!... It is your rig and everyone is happy again!

Has anyone bothered to work out why the boost pressures goes A-wall once EGR is blocked/restricted?... Funny how everyone notices higher boost pressures and installs more peripherals to drop it back down but don't question what and why it has climbed in the first place and what is happening else where on the engine management because of this Phenomenon?

To every action there will be a reaction!

Lets not forget that even if you block the EGR off successfully you will still get the oil residue into the intake manifold but it will look cleaner as there will be no exhaust gases being dragged across the oil to make it a thick black gue but a catch-can will reduce this anyway!

I am also "Not" a greenie saying you should do the wright thing and not mess with your engine as it is none of my business what people do to there vehicles and exhaust emissions but it is up-to the owner to know his reactions of his actions... Hence my time and effort to explain!

Exhaust emissions "was" a serious and very-big problem in the 70's causing very bad health and was well before carbon tax was invented or thought of as a revenue so i would not compare carbon tax as an emissions ploy but more of an enforcer to force manufacturers to produce an engine with more power/cleaning burning and more fuel efficient!.

Cheers

[Steve M Addicted PP Member Find all posts View Profile Close Steve M]

Jeez took me all morning to read that and still went over my head lol.....Just be done with it and buy a 4L V6 with heaps of grunt and no issues with EGR valves and will eat a D4D or 1kz either way LOL You pay for it at the bowser especially compared to the D4D but with $1000+ people are spending on chips, $1500 for exhaust, then modifying EGR's and stuff and initial purchase price for the diesels compared to petrols, then like today petrol is 15c to nearly 20c a litre difference (cheaper then the diesel) Im extremely happy with my petrol and I dont have my head under the bonnet except oil changes every 10k not 5 like the diesels and oops dont let me forget those shitty injectors/seals toyota dont want to know anything about and I can sit back and relax with a beer reading PP LOL...........Only kidding guys, all this EGR stuff and your obvious knowledge about these engines leaves me for dead. Hope you resolve the problem. Seems to be a major issue with this crap getting down into the motor/sump and blocking things up including air intake, dont have this issue with the 4L oops sorry. Kharma's gunna get me I reckon some where along the line lol. Have a great day guys....Cheers Steve

[Chip It Senior Member Find all posts View Profile Close Chip It]

SWR how many cars have you tested your theory on?

[SWR Banned Find all posts View Profile Close SWR]

Chipit

Quote chipit: SWR how many cars have you tested your theory on?

Answer skywalkerrun: Mine!...... i believe theory is based on results and having an understanding on the mapping of the engine not just voltage feed-back reading!

If you are so write and i am so wrong how come people are getting fault codes and issues?

Cheers

[Chip It Senior Member Find all posts View Profile Close Chip It]

The EGR system, the VVT System, the Injection system on modern diesels are the same. (Denso and Bosch) The only thing the D4d does differently than all other Jap diesels is that they stick a bloody pressure switch in the EGR system. This switch and the MAP sensor not getting enough pressure (from anywhere) is what cause the CEL to come on.

We have tested on over 100's of vehicles. We are not talking about opinions here. We started on Nissans because they had the common factory fault (ie blowing up !!) A special valve system is used to back up the Electronic over vacuum boost solenoid to eliminate boost spikes or turbo overshoot and causing EGTs to rocket skywards.

Now Chip It are working with Mitsu's (because that's what we have) and now the whole newtriton.net forum have blanked off their EGR for starters and many are starting to mod with setups, described below, to backup/bypass the factory VVT.

You should see the results we get when we disable the factory electronic over vacuum solenoid, working the VVT, making it work faster and come on earlier / harder. The cars are getting off the mark so quickly it is scary and EGTs are LOWER!

The system was first used on Patrols since their EGTs from factory were all over the place. People here may remember the hand grenades the Nissan motors have been. It was all because the VVT set up is crap. We use what is commonly called a Dawes Valve and in cabin bleed valve.

The in-cabin bleed is a needle valve (so can be adjusted on the run as desired) that controls turbo ramp up with the vacuum solenoid bypassed or removed just running the special valve system (called a Dawes Valve). It works by balancing the available vacuum at given RPMs against the actuator arm. We have used the very popular and good quality German made Flutec DV-06 oil valve (Be too expensive for a kit I think as retails around $70 mark! There would be something else out there that would do the job, just has to be very accurate so a fish tank valve won’t cut it. :lol: )

As you may know the Dawes Valve setup works by simply feeding positive boost into the vacuum side of the VGT vacuum actuator to achieve its set tension.

We also play with Dual Dawes Valves. With a dual boost Dawes system, a boost solenoid (just a simple on off air valve) simply cuts the positive boost pressure from a low pressure DV set at (wx) so a high pressure DV activates at its set pressure of (xy.) Solenoid OPEN, means VGT boost checks at (wx) and solenoid CLOSED means boost checks at (xy).
(wx) may be say 18psi, (xy) may be say 25psi.

Depending on the customers set up, ( in some cases dual chips to run separate systems like petrol injection ) one may either use a normal 12v switch, use a dual map switch with a chip or use a channel on our standard DPS chip via a relay. Obviously we need a voltage clamp on the MAP sensor beyond 22psi otherwise you get a CEL here because of excess flow.

How do we initially calibrate the needle bleed valve with the Dawes only set up? Simple. Close the valve fully, start the engine (warm) let it settle to idle then wind the needle valve anticlockwise until the VGT actuator STARTS to move back to its resting position. This will be close to being spot on.

Depending on fuelling and tunes etc, the set up can be refined by adjusting the actuator arm its self, but this arm adjustment part is not for the masses ... it really is for a Chip It dealer.

Best we keep things simple as possible for the masses. I’m even thinking a linear bleed that can’t be tampered with by customers if i can fine such a thing that suits. that way it is pre-set and fixed.

In any case, you can see that we have moved a long way past blanking EGR systems.

We have found bypassing the Electronic over vacuum boost solenoid dramatically reduces the EGT’s with the EGR blanked as the ECU cant choke the intake by reducing the boost under lighter loads in its efforts to increase the EGR.

This is what kills the Nissans.

After a time, after we finish the mods for Mitsu, we will tackle the D4d.

SWR if you have the time, we may be able to help YOU to move this along if you are keen to explore the potential.

I'll post some pics of the MN Triton set up later if you are keen.

[SWR Banned Find all posts View Profile Close SWR]

Gday chipit

Quote chipit: The only thing the D4d does differently than all other Jap diesels is that they stick a bloody pressure switch in the EGR system. This switch and the MAP sensor not getting enough pressure (from anywhere) is what cause the CEL to come on.

Answer skywalkerrun: chipit quote: "This switch and the MAP sensor" un-quote.... aren't they the same switch? Just a MAP sensor!... If you are also referring to the micro switch on top of the EGR valve then that switch only monitors the EGR valve movements and has nothing to do with pressure.

As you also stated that the Nissan's and Mitsu's VVT (Variable Venturi Turbo) are controlled by a actuating canister where as the D4D's are controlled by an electronic step motor.

Despite your claims of being successful on the Nissan and Mitsu's (I am not disputing this as i don't own one!) this same approach can not be used on the D4D's so i think it is unfair to have D4D's blocking there EGR based on your influence when it is clear the result is a global up-set and creates conflicts on the engine management system. (Are you prepared to hold responsibility for anyone that carries out this mod on D4D?).

Quote chipit: After a time, after we finish the mods for Mitsu, we will tackle the D4d.

Answer skywalkerrun: Even though you claim success on the other brands it does not apply to the D4D's so i believe my concerns with the EGR restrict or delete still stands!

I personally feel sorry for all those guys who trust in your mod's (D4D's) when they are clearly not certified as safe.

On that note given that what i have written in great detail on what i believe is happening to the D4D's (And strongly believe to be true) concerning the EGR delete or restricting i will now sit back and watch this thread with great interest as i believe i have addressed all of my concerns starting from the very beginning of this thread when it first started so it is now down to the owner given that warnings have been brought forward!

Cheers

PS no offense but not keen on the Triton or Nissan stuff as this is a Prado forum and i can go over there if was interested.

[Ozpat Advanced Member Find all posts View Profile Close Ozpat]

Jeez took me all morning to read that and still went over my head lol.....Just be done with it and buy a 4L V6 with heaps of grunt and no issues with EGR valves and will eat a D4D or 1kz either way LOL You pay for it at the bowser especially compared to the D4D but with $1000+ people are spending on chips, $1500 for exhaust, then modifying EGR's and stuff and initial purchase price for the diesels compared to petrols, then like today petrol is 15c to nearly 20c a litre difference (cheaper then the diesel) Im extremely happy with my petrol and I dont have my head under the bonnet except oil changes every 10k not 5 like the diesels and oops dont let me forget those shitty injectors/seals toyota dont want to know anything about and I can sit back and relax with a beer reading PP LOL...........Only kidding guys, all this EGR stuff and your obvious knowledge about these engines leaves me for dead. Hope you resolve the problem. Seems to be a major issue with this crap getting down into the motor/sump and blocking things up including air intake, dont have this issue with the 4L oops sorry. Kharma's gunna get me I reckon some where along the line lol. Have a great day guys....Cheers Steve

I'm with you on that one, Steve. Diesel was a bit cheaper than petrol up until I bought the D4D and then got dearer like you said by about 20c. I'm also lumbered with the turbo lag which I loathe. I'm only comforted by the knowledge the D4D should outlast the V6 (hopefully) but boy do we pay for it.

Cheers, Jim.