Blocking Off EGR Valve-Emissions?

[Benesesso]

Finally got around to determining why my 1990 Turbo Supra was using (not leaking) about a quart of coolant a day (~50 miles). A coolant test for exhaust gases in the radiator was negative. But I *knew* it had to be a BHG--at only 70,000 miles.

Pulled off all the stuff required to get the spark plugs out. Hmmm, no.6 plug looked different from the others. Shined a flashlight down the hole and whadda you know--looked like a lake in there.

So, it has taken me all day to get the intake side off. That EGR valve at the rear of the manifold is a real stinker to remove. I plan on making a small flat plate out of stainless steel and just blocking the port off.

Has anyone done this and then had the emissions tested? I *think* the EGR is supposed to reduce NOx at idle. The car just passed its emissions test with flying colors, but I'd like to know what to expect w/o EGR.

[Strannik]

from what i read you only need EGR to pass emissions if you're in California, since you are in Arizona you can just block it off. just confirm it with someone local, cuz i'm far away from US and we don't have EGR here at all
it will be good mod to remove it since it will lower your air temparatures and give you more oxygen in the a/f mix

[supra_91]

i blocked mine off. it will barely, if at all, increase your emissions

[Benesesso]

Thanks for the quick replies. I hope the turbo/exhaust side is easier to remove than the intake-I busted hump today. At 65 years I'm gittin' too old for this stuff---.

[mrnickleye]

For every emission test in the USA, you need to have the EGR on a Supra. Actually, whatever was equipped from the factory must be there, and working.

Now...if the testing person is incompetent, blind, lazy, our on the take ($), that's another story.

The car was designed to run with EGR, so removing it won't get you any HPs. (unless you are building a real high HP motor)

Without it, your NOT getting more oxygen in you fuel mixture. Without it, in hot weather, you might get some pinging under load (hard acceleration).

It does NOT operate at idle.

Check this out...
http://www.asashop.org/autoinc/dec97/egr.htm

[Strannik]

thats debatable
EGR was installed only in supras shipped to US and Europe
if it had anything to do with safety(eg pinging) i'm sure japs would put it on all supras.

Here is the quote from supras.nl:

First thing to remove is the EGR cooler. I assume you won't put it back on your car, unless you live in California and you have to pass the yearly emission checks. Over here in Holland you will pass without the EGR system, so this is a good idea. You really don't need the EGR system and removing it removes weight from the vehicle as well. And that's good for you gas mileage, so saves the environment! Yeah right ;-) Note the EGR system only limits the NOx gasses on idle. It does not help CO, CO2 or CH emission checks. In the Netherlands, cars before 1992 must only pass CO checks, so the EGR system is not needed here. Please check how this applies in your country before removing! An other arguments for removing the EGR system is preventing the intake manifold from getting black on the inside (bad airflow after loads of miles)

[Benesesso]

Interesting. If a ported vac. signal is used, then it seems that EGR has no effect at idle.

Hopefully the oxygen sensor/knock detector (I assume Supras have one) will work to protect things.

Anyone know if removing it from a 1990 will set a computer code?

[mrnickleye]

Check the egr facts thread in the FAQs section. There are some links to learn all about it.

Yes, the knock sensor will detect any pinging, and retard the timing to protect the engine. But it is a little slow, so there can be pinging for a moment or 2 before it retards.

If you get pinging, you could run premium fuel, and perhaps octane booster. You could retard the timing to 5* (and 0* if needed).

Removal is generally done for looks, and cleaning up the engine bay.

EGR does not work at idle.

[Benesesso]

My only reason for blocking it off is because it's so difficult reaching the bolts. But after removing so many bolts, hoses and electrical connections I suppose 2 more won't make much difference.

Just managed to get the exhaust pipe off now--I'm taking a little break. Then comes the 2 difficult inner turbo bolts. Then the exhaust manifold (some of those bolts came off relatively easy). Hopefully by tonight I can actually get the head off and see how much head/block damage there is.