EGR question

[vrinner]

My understanding is that the EGR valve is only to make the car cleaner burning. Since my 86 is just a track car, can I just take all the egr stuff off or will there be some other ill effect?

Thanks!

[SVOeric]

it can have some negative affects on gas mileage -- but other than that-- there's no problems I've heard of.

The last time I did this, I just made a block off plate for the EGR, and covered the holes.

[vrinner]

Where

Blockoff plate to cover at the manifold?

[slovanova]

I will be taking my EGR off too. I just don't feel like putting it back on when I get my hybrid on. I had a friend make me a block off plate using an old EGR as a template. As long as there aren't any major disadvantages to taking it off, I will go through with it.

[Pat_in_L.A.]

The EGR is there to reduce combustion chamber temperatures, which would reduce pinging (knock?).

Let's find out where and when the EGR actually is operative in your application.

[vrinner]

How would I go about finding when it is operative?

[SVOeric]

Re: Where

Originally posted by vrinner
Blockoff plate to cover at the manifold?

yea.. block off plate at the manafold, and of course-- a plug in the header/manafold

I'm not sure about reducing temps? Someone would have to explain that one to me

[KraigW]

egr & pinging

When my EGR solenoid went bad, I encountered some pinging. I was running premium fuel + octane booster and timing set at 10 degrees. I couldn't figure out what the problem was. The factory repair manuals referred to possible EGR problem. Sure enough, the EGR valve wasn't actuating. Valve wasn't clogged, so I traced the problem to the EGR solenoid. After that experience, I guess I wouldn't recommend running without the EGR system.

Oh, and by the way, while I was researching emission testing, VET websites did mention that the EGR system assists in keeeping temperatures down.

I was able to pass the VET sniff test without a catalytic convertor or my EGR valve functioning, though.

[AT6svo]

EGR

The EGR is not used during cold start or at WOT. The EGR is only used when the ECM is open loop, typically that is once the engine has reached normal operating temps in non-WOT.

The EGR "cools" by re-introducing hydrocarbons (exhaust) back into the intake tract, hence reburning any unburned fuel and takig the place of regular O2 during the combustion process.

I really don't remember there being and EGR soleniod, thought it just tapped off of the vacuum tree at the firewall. Unsure about that fact.

[SVOeric]

there is a egr solonoid ---

I can see how air with no oxygen would not burn as hot -- but pushing hot air (from the exhaust) into the intake seems like it would negate any positive affects ??? (that's why we have intercoolers!!)

just trying to hit it form a common sense angle.

I may be completly wrong -- but I'm just tryng to figure out why?

[svohoo]

think I can shed some light...

The purpose of the EGR system is to reduce oxides of nitrogen (NOx) in the exhaust by mixing in an inert gas to reduce the combustion temperature. The most readily available (and free) inert gas is, voila, exhaust. NOx mostly refers to nitric oxide (NO) and nitrogen dioxide (NO2), which is extremely toxic. It forms a reddish brown haze, is very irritating to the eyes and respiratory system, and is a cause of acid rain, which I have seen destroy a new paint job. NOx also reacts with hydrocarbons in the exhaust (and wherever else it encounters them) to form ozone, which we need in the upper atmosphere but can be deadly at ground level. If you’ve ever heard of someone having a fatal asthma attack, there’s a good chance exposure to ground level ozone was at least a contributing factor.

It sounds contradictory to logic, but the EGR does actually reduce the combustion temperature in our engine - the heat added by the exhaust is much less than the extra heat that would be generated by not having the EGR. Disconnecting it could conceivably cause detonation and keep it from running right. My opinion is that you are better off leaving it hooked up. In general, I think we should all be doing the environmentally responsible thing and keeping our cars as clean running as we can make them. One of the wonders of the EEC system is that it can let our cars go really fast without dumping all sorts of crap into the air. I confess that you probably could legitimately call me a liberal pinko commie tree hugger, but that’s my $.02 worth.

Now, get out there & wipe up the track with all those "Brand X" cars! Good luck.

[Otto Man]

David
Nice explanation!
I'm up here in Ellicott City. Come on over this weekend or next and we can play under my hood replacing injectors and stuff!
Chris

[svohoo]

Chris,

Thanks. I'll try to find some time when I can come out to play & let you know. Do you work nearby? I work in Elkridge; maybe I could get out at lunchtime.

[Otto Man]

David,
I work at Washington Navy Yard and get back up this way around 4:00 PM. You can swing by any nice afternoon or on a weekend.
I see this redo project stretching. Already found a complete new set of hoses and I'm gonna redo those nasty pipes that run along the starboard side of the valve cover. I haven't found the water temp sensor yet. Is it back there below the lower intake?
Chris
My other steering wheel for a shop manual!!