What are the conditions that cause the EGR to open and allow exhaust gasses into the mixture? does it open under full throttle or low throttle? ETC.  Does the chip control it entirlely? what temps matter that kind of thing.  Thanks.

You are asking for a general answer to a very tricky unit. There are many variables for the control of the EGR.

My suggestion to you would be to download TunerPro RT, aquire the TGP.ecu file, and either a stock .bin set for the TGP code or have a look at any of our .bin files. You will see all of the areas that control the EGR and more importantly...WHY! :wink:

Answer, the egr does not open at idle or open throttle, period. It is difficult to say when it operates but with everything up to temp it will operate at cursing speeds and light throttle and can actually enhance gas mileage and engine life by reducing the temp in the combustion chamber. Under no instances will it increase  power so don't disconnect it you may actually be harming your motor. :(  Mine is connected and passes smog and most of you know how well it runs. There is absoultly no reason to disconect it unluss you want to create more smog. :evil:

Jud

Edit: open = WOT

And you have to admitt that if I hadn't corrected this I would have got ten post telling me I was wrong.

Dave this inability to edit is getting to me, what is the reasoning behind it :?: Don't like it at all.  I almost never type anything correct the first time and I have damn near given up posting here because of it. :roll: Not having that ability makes me want to go elswhere. A spell checker would help.

Have to say seems like it has picked up since you have become a mod. Keep up the good work. :D

WTF   Now I can edit this post but I can't edit the one I want :?: Did somebody read it that fast :?:

Jud

how does it cool combustion chamber? I really know little about what good an EGR does

Quote from: Prospeederhow does it cool combustion chamber? I really know little about what good an EGR does

Man you came back with a question before I could even edit my post. :wink:

Answer the ex gas is one hellava lot colder than the combustion gases. Therefore cooler chamber and better combustion and more power and less nox. Thats why you have more power on a cold day.

Any other questions, I am  no expert but I have done some research. I used to drag race in Ca, and smog requirements are the strictes, shit the assholes wrote the book, Texas is not easy although I have got by with a 289 duration cam with just stock smog equipment. If you stood behind the car it would burn your eyes. I barrrrrley passed. Don't think this would fly in CA.

Jud

if it is exhaust gases entering, wouldn't that increase temps in the cylinder? since it is hot air versus cooler air from the intake? Granted air isn't too cool after the turbo but seems it should (could) be cooler than gases that have already been through the combustion process?  Reason I'm asking and such is because my EGR hose is broken and i dont have a replacment now.


how come you cant edit posts? I can... infact, i just did.

I believe you have to be Signed in/"Logged In" for the "Edit" option to pop up :?

Yea MAN, Jud speaketh the truth, follow his words 8) !!

Why is it this way/EGR has a cooling effect on the combustion chamber!  This will make sense, exhaust gas already has had the oxygen burned up when in it did its hot thing/making a boom in the combustion chamber.  So when exhaust gas is sent back into the combustion chambers it reduces/displaces the amount of oxygen in there, so the charge mixture will not burn as intense/be as hot.  So yes the boom is not as hot, and this also cools the head down a bit :!: , sort of like us running a colder stat to cool the water running in the water jackets of the heads :idea:.  And no don?t go freaking it kills power because of lesser boom heat, that is what the old-school thought was and the cause of so many people killing it/blocking off the EGR.  DON?T DO IT, it will not hurt power or lessen gas mileage, and it only works at light loads and when the engine is up to a pretty warm temp/hot, and its nice to pass emissions if it's required where you are, but even if you don?t get sniffed, no reason to delete it.  Many also do it to sound like they are cool :roll: , ahhhh, no not cool!!!!  What little heat it sends into the intake (not like the EGR dumps a huge amount of exhaust in there anyways!!!!) quickly goes away soon as some fresh air flows through there, no big deal there either!

Jeff M

okay, so jeff, you got some EGR hoses around I can fix my problem with???
:lol:

Quote from: tyroeliteokay, so jeff, you got some EGR hoses around I can fix my problem with???
:lol:

Yea, new and used, PM me if you dare :wink:

Jeff M

Test Car:
'93 Lumina 3.1 N/A (3 pintle digital EGR.)

Light accel = Sol 1 On (Open)
Slightly harder accel = Sol 2 On
Even Harder accel = Sol 3 On

Pressing the accel even harder can make all the sol on at one time.

When you get up to speed it seems like they are not really used till you slightly accelerate again.

During Deceleration they are not used (closed) from what I've seen so far.

The older vacuum EGR works in the same manner I imagine except that it only has one pintle, the harder you are on the throttle the more it is open.

good deal, thats what i needed to know. :)  still waiting on Jeff to get back to me about a replacement hose but I think I may try a block off plate for the time being.

I fail to see how it will affect emission testing?  Especially considering our '88 Beretta GT hasn't had one for 2 years now and the emissions readings are non-existant....literally. :shock:

This link helps explain how the EGR affects emissions http://www.misterfixit.com/egrvalve.htm

My EGR works, but I'm still glad I live in a state with no emissions testing! :D

Quote from: z284pwrI fail to see how it will affect emission testing?  Especially considering our '88 Beretta GT hasn't had one for 2 years now and the emissions readings are non-existant....literally. :shock:

Here they actually run the car on like a dyno. They simulate crusing and light acceleration to make sure the egr is operating.  Might pass without one but I doubt it. It's getting tougher to pass these test.

Jud