To EGR or NOT to EGR?

[Retta88GT]

Maybe I'm the one who killed the BStuff board, because I posted this question there and I couldn't get on it anymore...

Has anyone here tackled this somewhat taboo question?  I've read some mentions about it, but nothing extensive.

I'm replacing my throttle body and doing some very heavy top engine cleaning right now...and I am debating whether to block off the EGR (...keeping it reversible for emmissions time, of course). ÂÂÂ

First, I'll let it be known that I believe that Global Warming is due to the fact that our sun is nothing more than a giant piece of coal that is getting hotter as it burns to it's eventual death a few billion years from now.  However, it's estimated that we only have about 5000 more years to live on this rock before it gets too hot for us.  ÂÂÂ

In other words, our cars are not destroying the Earth, and neither is your hairspray, barbeque, or your cologn.  Certainly not any moreso than all those factories and public transportation.  The progression of our own sun is what's going to do us in, and there's nothing we can do about it.

So, with that said.... ÂÂÂ

I have run my car without the EGR, and although I still have my hesitation and bogging problems (which is why I'm replacing nearly everything related to it right now), it DOES respond and run much better.  I also know that it saves my intake from being caked with carbon from the used exhaust going back through. ÂÂÂ

However, I am not a mechanic (I'm going by the steps via a Hanes manual with my spring cleaning routine)...nor do I play one on TV...and I haven't stayed at a Holiday Inn Express recently.  So, I know there's a lot i don't know about the subject. ÂÂÂ

Such as...

1.  If I do block it off, what else do I have to do with the various vacuum lines that are associated with it...and WHICH vacuum lines are associated with it?

2.  Do I also block off the line coming from the exhaust?

3.  Assuming there is a "give and take" with this...what are the undesirable side effects I may get in return for the better performance?

Before I'm told that my engine may blow up due to higher temperatures in my cylinders, isn't the engine designed to deal with those temperatures to begin with? ÂÂÂ


Thanks, guys!!

[1988GTU]

There's only one vacuum line going from the TB plate to the EGR.
You will have to block the port at the TB plate so you don't find yourself with a vacuum leak.  I the plate to eliminate the need to plug the hole and also to keep from looking "suspicious" if you have inspections.
If you make a plate and use a gasket on the plenum side and a gasket on the EGR side while installing the plate in between, you will not have to block off the manifold port and you can keep the "factory" look IF you ever so need to for inspection purposes.  Using a drill, rotary tool and some aluminum plate can do the job well done.  However you MIGHT need to have the dtc set at a higher number so it never flashes a SES.  Although, I have done it without a code popping up.  
You could see higher nox emission and maybe* .009 worse mpg, but I think from not having all that carbon build up from the egr exhaust passing through the intake is a toss up.  Also the intake plenum will see slightly lower temps too.

If you had obd2 it would be a different scenario and would do slightly more harm than good.

[Z26-T]

Talked to a tech at my work with the hesitation, bogging stuff (my car does it slightly too). But apparently the early 90-93s, while under warranty, we would replace the IAC (idle air control) and the pcm (powertrain control module). But mine being a 95 with the pre obd2, hopefully my pcm isnt as junk as those obd1s were... but anyways. I replaced the IAC in mine and it seems to run better. Havn't seen any of the hesitations that i used to, but am still testing it.

[Beretta__z26]

so really, how many degrees cooler would the Intake manifold see? as far as performance...doesnt the EGR close when  at 80% throttle or higher? so no exhaust recirculation when at the track and such. so i heard, could be wrong. a buddy of mine is a mechanic and we had this convo when i was replacing sensors, and he said its just not worth it. but you know...im just one person that probably has no idea what im talking about

[Z26-T]

If you're worried about intake manifold temp... I remember seeing a picture where a kid had used hvac ducting for a house to create a "cold air ram" to reduce external engine temps... said he would do long distance drives and touch his intake and it was cool...

[Retta88GT]

I got my new throttle body today ($50 on Ebay...brand new!!  WITH sensors!!), and found something interesting.

Ironic, too, since I started this thread about the EGR and how to block it off.

The vacuum plate on the top of the throttle body, which the four-plug vacuum fitting fits in, is NOT drilled through for the EGR line.  Was this throttle body intended for a non-EGR application?  

Anybody know about this?

Thanks!

Shannon

[1988GTU]

Yep, and you could have just swapped the top plate for ALOT cheaper.  Live and learn.

[cramez]

90 and up didn't have the line for the EGR because it's digital and not vacuum controlled.  87-89 2.8's all had the vacuum controlled one.

[BerettaLove32]

On a side note who knows what size wrench is needed to get the EGR off the exhaust manifold. I only have up to a 19mm and it's too small. I need to get my TGP crossover on there.  

[Retta88GT]

(1988GTU @ Apr. 08 2008,19:52)QUOTEYep, and you could have just swapped the top plate for ALOT cheaper.  Live and learn.
Swapped the top plate for what?  I can still put the old one on it if I want.  I intended to get the new throttle body.

...and it only cost $50 new with the sensors.  That's almost half of the two sensors alone from Auto Zone.

Actually, the new plate without the hole drilled through is a bonus.  If I decide to go without the EGR, I don't have to worry about plugging the line.

[heavywoody]

(BerettaLove32 @ Apr. 09 2008,03:03)QUOTEOn a side note who knows what size wrench is needed to get the EGR off the exhaust manifold. I only have up to a 19mm and it's too small. I need to get my TGP crossover on there.  
I dunno about that year, but I just put a 96 EGR pipe on my car so I can have a bolt-up EGR setup instead of the half-assed setup I had before.

The 95 pipe was 22mm, and so was the 96.

[JeffD]

If you get rid of your EGR valve your combustion temps will be much higher, this will cause lower efficiency combustion, the engine may ping a little until the computer finds a retarded timing  that will give you a little less performance, that is negated by the lack of inert (nonburnable gasses) allowing for more air fuel to be used in each cylinder. on the earlier cars of the seventies getting rid of this and the air pump freed up some horsepower since everything was slapped on an existing engine anyway. our engines are designed with this stuff in mind.
pretty much unless you give me dyno numbers and track times I think it's a wash.
the only time I would do it is on a hybrid engine where your original controls and hardware will not work with the new intake.

[Retta88GT]

(scberetta3800 @ Apr. 09 2008,18:26)QUOTEpretty much unless you give me dyno numbers and track times I think it's a wash.
the only time I would do it is on a hybrid engine where your original controls and hardware will not work with the new intake.
I don't race or anything like that.  I just know what it feels like when I'm driving.  I think the real problems I'm having are going to be addressed with the new injectors and regulator I'm putting in, as well as the new sensors I've put in everywhere.  But the times I've unplugged the EGR and blocked the vacuum line, my car has a lot more punch on acceleration and feels a lot smoother.  

I'll know more once I get it back together and see if I got rid of my hesitation problems.  Then I can really try it both ways.

Thanks!