EGR To have or not to have?

[oldpunk]

Just removed an cleaned the EGR valve of my trusty Firoino 08 multijet. It was so fowled up it had driven my ecconomy down to 35 - 43 MPG, it was slugish and poor from cold. Designed to reburn particulates in exhaust gases in order to save the planet, it caused me to burn @£500 in diesel for no good reason, which is also bad for the old rock is it not? With my turbo now not over boostin due to a stuck wastegate should I blank of the EGR to omit the gulp of hot gas it gives my engine killing my MPG and heat charging my intercooled boost.

My mutijet is now flyin with 45 - 60 MPG easy, will ditchin the EGR improve performance further of or just stop it getting sutted up?

 

[dave]

an 08 car/van will probably put engine light on if you block it off

 

[oldpunk]

an 08 car/van will probably put engine light on if you block it off

The EGR on my van has only the actuator loom connection, when I disconnet that I get no fault light. If the EGR cannot open to allow gases through then what sensor would pick up that the EGR is unoperative?

 

[dave]

this is from the croma section, but your car/van may be the same as its even newer

I posted somewhere here on this website exactly how the Croma EGR works. You can NOT just blank off the EGR port. The ECU does not measure EGR gas volumes but it does calculate an expected EGR volume based on what it has demanded and what has flowed through the MAF (main airflow sensor). Simply if 100% airflow = 10% EGR and 90% MAF then if you blank off EGR then MAF will be 110% of expected value. Over time the ECU will deduce that the EGR circuit is not supplying enough volume and the ECU will throw an EGR fault.

The nearest you can get to blanking off the Croma EGR, without resourting to an ECU map program modification, is to fit the later "bullet" plate gasket.

Again details are posted here (somewhere) by me.

 

[oldpunk]

this is from the croma section, but your car/van may be the same as its even newer

Yo,
Get the logit, excuse me being if I seem picky, So the Maf sensor knows the volume mass of air, is it the ECU with the MAP sensor and rev counter that does a calc. to establish the expected manifold pressure of that air and reburnt exhaust gas?

 

[dave]

i dunno i bought new egr fitted it and blanked it off to keep it new, my engine light came on and that man told me that was why

 

[Peter Pick-Up]

For the 1,9 Diesel 16V and 8V engines, Fiat has restricted, modified EGR gaskets for sale, the 8V has a gasket with one hole in it, the 16V has a gasket with 4 holes in it.
By completely blocking the EGR, you WILL get a computer light.
Might worth considering those restricted gaskets!
I recently have one on my 2004 Alfa GT jtd with the 1,9 16V engine, can't tell much difference, but everything counts...!!

 

[oldpunk]

For the 1,9 Diesel 16V and 8V engines, Fiat has restricted, modified EGR gaskets for sale, the 8V has a gasket with one hole in it, the 16V has a gasket with 4 holes in it.
By completely blocking the EGR, you WILL get a computer light.
Might worth considering those restricted gaskets!
I recently have one on my 2004 Alfa GT jtd with the 1,9 16V engine, can't tell much difference, but everything counts...!!

You and the other guys were right, the car needs to be run for a while with the EGR not working for the MAF, throttle sensor, rev counter, engine temp sensor and others to do a crafty calc, to say your EGR is not pukin sut into its own manifold. I accept that when the EGR works its not gonna effect performance, the trouble with this POLITICALY CORRECT collection of valves, tubes and actuators is when it blocks the manifold neck with that dirty mix of breather gases and sut. The way I am drivin my little van with its new lease of life should keep the sut at bay.:slayer:I can't get over my fuel consumption now the EGR and turbo waste gate are sorted. 45 - 55mpg easy around town and thats with a heavy right foot. I wonder what MPG I could get if I drive like my 75 years old dad:idea:

 

[s130]

Sorry but I lost the plot / intent of your post.

Are you saying that you have blocked/removed your EGR and over time the engine ECU becomes happy and clears the EGR error? If so please provide more information like miles travelled / time since EGR blanking or removal and time/miles take for ECU to recalculate and accept/remoce the error.

You and the other guys were right, the car needs to be run for a while with the EGR not working for the MAF, throttle sensor, rev counter, engine temp sensor and others to do a crafty calc, to say your EGR is not pukin sut into its own manifold. I accept that when the EGR works its not gonna effect performance, the trouble with this POLITICALY CORRECT collection of valves, tubes and actuators is when it blocks the manifold neck with that dirty mix of breather gases and sut. The way I am drivin my little van with its new lease of life should keep the sut at bay.:slayer:I can't get over my fuel consumption now the EGR and turbo waste gate are sorted. 45 - 55mpg easy around town and thats with a heavy right foot. I wonder what MPG I could get if I drive like my 75 years old dad:idea:

 

[T14086]

Designed to reburn particulates in exhaust gases in order to save the planet

Nox gases actually.

 

[GrandeGuy]

Blank off the EGR then get it remapped to forget it ever had an EGR.

 

[oldpunk]

Blank off the EGR then get it remapped to forget it ever had an EGR.

Me thinx I wil remove and blank off EGR if it suts up again quickly and re map. Pre loaded my turbo actuator to deliver something approaching 1.25 Bar over the stock 1 bar, running up to temp just fine. Fuel consumption is steady now EGR valve blockage to manifold is clear. The bloody little engine re born, like a new car its flyin. FUN FUN FUN:slayer:I bet the dealer who quoted a new turbo prob new the EGR would probably be blocked and the wastgate was stuck. Its not rocket science once you have got your hands dirty.

 

[Shadeyman]

The 8v JTD can be completely blanked off with a blanking plate with no issues as its unable to detect that the EGR is blanked off.
http://www.ebay.co.uk/itm/120928729531

However, the 16v mJTD can detect a completely blanked EGR so a restrictor plate should be used.
http://www.ebay.co.uk/itm/110902313955

The 16v mJTD is able to detect the increase in O2 in the exhaust gases when the EGR is completely blanked off and the EML is lit.

Many people think a blanked EGR is detected via the MAF because of a change in airflow, if this were true the 8v would surely detect a blanked off EGR(it doesn't).
A remapper told me he was 99% sure that blanked EGR was detected using the lambda sensors.
The EGR recycles exhaust gases to reduce NOx gases. It does this by reducing the combustion temperature. There is also a reduction in the amount of O2 in the exhaust gases when the EGR is operating. The 16v mJTD has 2 lambda sensors(O2 sensors) pre and post CAT and it is able to detect any increase in O2 caused by blanking off the EGR. This is because there is an expected range of O2 in the exhaust when the EGR is working. When it is completely blanked off the amount of O2 in the exhaust gases increases out of the expected range and the EML is lit.

So a plate that allows just enough gases through the EGR to fool the engine should be used.

Fit a "Restrictor Plate",

 

[Peter Pick-Up]

Fiat part# 55225287 restricted EGR gasket for the 16V jtd, costs about Gbp 10.
From m.y. 2008 it should be factory fitted.
Btw, my 2004 stage 3 jtd has no lambda sensors at all, so I effectively have removed both catalysts...!!

 

[s130]

Many people think a blanked EGR is detected via the MAF because of a change in airflow, if this were true the 8v would surely detect a blanked off EGR(it doesn't).:

Well what I wrote about EGR calculation on the Croma came straight out of Fiat's eLearn Technical Manual.

I quote:

OPERATION
At coolant temperatures of > 20°C with the engine speed between 800 and 3000 rpm, the injection control unit operates the E.G.R. solenoid valve with a square wave signal.

The variation in this signal allows the E.G.R. coil to move a shutter, thereby regulating the flow of exhaust gases from the exhaust manifold to the intake manifold; there are two results:

less air is introduced;

the combustion temperature is reduced (on account of the presence of inert gases) resulting in a decrease in the formation of NOx (nitrogen oxides).

The injection control unit is constantly informed of the quantity of gas recirculated through the information coming from the flow meter: in effect, if there is an intake of a certain quantity of air (Qam) for a given engine speed and the value sent by the flow meter (Qar) is lower, then the difference (Qgr) is the value for the quantity of gas recirculated

Qam - Qar = Qgr

Qam - Theoretical quantity of air memorized

Qar - Actual quantity of air

Qgr - Quantity of recirculated gas

The atmospheric pressure signal is used for the operation of the E.G.R. solenoid valve to recognize the condition of driving at altitude in order to reduce the quantity of gas recirculated and to prevent engine fumes.

Unquote:

Now it could be that O2 also plays part in the error determination but O2 can increase for other reasons besides EGR volume. It is my understanding that EGR affects primarily NOX content which is not sensed by an O2 sensor.

In addition lambda sensors for a diesel engine has to be a "Wide Band" sensor. In most cases they are only used on Euro 5 emission spec vehicles. These sendors have FIVE wires. My Croma does not have such a beast so for me (at least) the calculated EGR flow is the prime determinator.

 

[Shadeyman]

So an 8v is not able to detect the increased air flow but the 16v is.

So why is the 8v unable to detect a blanked EGR? :chin:

 

[s130]

I think 8V don't detect the EGR loss of EGR flow because no 8V FIAT diesel engine is fitted with a DPF filter. DFP required radical ECU code changes not only because of the DPF itself but because the assocated CAT changes as well. A DPF has catalytic content as well as pure filtering abilities. DPF, EGR etc. are all inked together to ensure that DPF regen is done correctly and under the right conditions. I think this is also why when a DPF is mapped out EGR is also removed.

Whilst I can't put my hand on my heart and swear on the bible most of the info I have read is supportive of what I have posted.

Regardless of the indivdual facts it is clear that on some Fiats the EGR can be blanked off (8V diesel) and on others (16 valve diesel) it can not be and can only be restricted without ECU remapping.

All this complexity, fuel wasting (DPF regens and low mpg), inlet contamination and swirl valve stress due to regurgitated soot via the flawed EGR system etc. is putting me off ever owning a diesel engined car again. This is even before we get to clogged DPFs requiring expensive replacement, oil dilution dues to excess diesel fuel followed by engine siezure, etc. is even discussed.

To top it all off to be legally insured any mods have to be notified and the insurance companies will then decline insurance or significanlty increase you premium.

If I were a Euro politician I don't think I could have written a better pointless and ill thought out DPF/EGR policy based on current technology that is costing the environment in both fuel consumption, waste of rare earth metal resources, cost of trashed siezed engines, cost of replacement DPF filters, gummed up EGR valves, failed swirl valves (very expensive to replace) etc. etc.

 

[oldpunk]

Don't you just LOVE EGR until it chokes up you engine and kills your MPG.:bang: Its a PC gagget in a world of rules and legislation.

 

[T14086]

To be fair (and I like putting the other side of the argument across, no matter what I personally think) what about say the MOT tester who will do 2 or 3 diesel tests a day unintentionally breathing in the exhaust fumes while carrying out the smoke test. Surely it must be taking a toll on his (her) health and if so how much of an affect is it having on those who live in congested cities etc?

 

[Peter Pick-Up]

To be fair (and I like putting the other side of the argument across, no matter what I personally think) what about say the MOT tester who will do 2 or 3 diesel tests a day unintentionally breathing in the exhaust fumes while carrying out the smoke test. Surely it must be taking a toll on his (her) health and if so how much of an affect is it having on those who live in congested cities etc?

What about planes, ships, factory's, Power plants. etc. etc....!!
On 1,9 16V engines until stage 4, catalysts can be removed, and EGR should be restricted at least. ( like mine..!!)
I do run my jtd on V-Power Diesel fuel though...!!