EGR valve discussion

[himynameisdaniel]

Blame the EPA.

By allowing exhaust gases to go back into for re-combustion it means the catalytic converter can heat up quicker on cold start.

Some countries\states are very strict on EGR and emissions testing (ie California) they have a plethora of emissions specific tests.

South Australia is very lucky because we only will get tested if your car has a major defect. which needs to be issued by police.
For those who keep their cars in good condition and dont draw attention to themselves these tests will never occur.

[billy boy]

do the ralliarts have these?

[himynameisdaniel]

all modern road vehicles have these

[sleeper]

stay on topic please, i`ve split the thread into 2

EGR discussion http://clubcj.net/viewtopic.php?p=386128#386128

[aspir3]

I wonder if we could remove the butterfly valve in the ERG valve and use a steel gasket plate to block off the hole.

Anyone have a schematic drawing of the valve?

[burfadel]

If it is electronically controlled on modern engines, if it is possible to change the electronic operation wouldn't that be better for warranty issues etc?

[aspir3]

If it is electronically controlled on modern engines, if it is possible to change the electronic operation wouldnt that be better for warranty issues etc?

I would think so.

Why are you concerned about warranty? What do you think it can cause? I can only see it being good for the engine and more likely to actually prevent damage when deactivated.

[sleeper]

it can probably be switched off in the ECU.

if u know its address.

then u might have to switch off the appropriate CEL as well

[burfadel]

Here's an autospeed article about it:
http://www.autospeed.com/cms/article.ht ... 2&A=112730

Then there's this forum post:
http://www.evolutionm.net/forums/evo-dy ... elete.html

So I guess the only time you really want it open is in cruise mode, as long as the opening/closing is tuned. That said, having it stuck open means the car simply won't run as I found out :S.

[toc]

It's also good for fuel economy though.

The engine needs to breathe air in to maintain engine speed.
If you breathe in outside air at 400g, you'll need 27g of fuel to ignite that 400g.
Now, if you fill the cylinder with 200g of inert exhaust air and 200g of outside air, you'll need just 13g of fuel.

It's not exact like that, but the inert gas being placed into the cylinder serves a low load purpose for fuel economy, recirculating it means less oxygen is drawn in, less fuel required to ignite.

It can affect driveability - if it was forced open, it will go to a near stall situation (too much exhaust not enough oxygen), so to get around this, EGRs are not used in idle and very low load situations (crawling along in traffic - no EGR).

If your goal is fuel economy, leave it there.
If your goal is performance, just remove power to it, which should be fine (I don't know if the ECU looks for evidence the EGR is fine and throws a code - so your own risk if you unplug it).

With it unplugged the engine damage will be zero - none at all.

[aspir3]

The way i read it if you delete the ERG valve you may have to change other things in the ECU like MAF maps and TB controls.

I'm no expert though, waiting for Merlin to educate us what needs to be done and why.

[burfadel]

So based on the leaving it there or removing it for fuel economy/performance, wouldn't the ideal thing be to modify how much it opens? From what I found it only affects performance if it doesn't close properly, which unfortunately due to the nature of the EGR valve seems to be common.

[toc]

Read the autospeed article and they note sticking (and it will, exhaust can be like varnish in the right temperature) - so clean it with carby cleaner regularly will stop the original issue.

[aspir3]

Yes cleaning it is a good idea but stopping it from getting the inlet manifold dirty is even better.

[merlin]

If you simply disconnect the cable you will probably get a CEL, someone please check this, both 2L and 2.4L.

If you block the feed holes the EGR code is still active and there are spark and fuel modifiers in play and suddenly the "air supply" is absent.
That will likely be detrimental to the overall tune.

And so the best fix is to find in the rom where the EGR enable flag resides and set it to zero. No more EGR code so no CEL. Then you can simply remove the valve and fit a blanking plate in its place.

Job done.