EGR System Facts

mrnickleye · 02-07-2007, 06:01 AM

I'm certain that those people that are doing some intense mods to their engines will be focusing on the best solutions, using 'fuel management' systems, and such, and thus can easily remove the EGR system and have no running problems.

But...to be a guy that opens the hood and rubs his hands together, and says "what can I remove today" ? Well, he just needs to do some research first.

Its like throwing a K&N filter on, and expecting to gain 20hp.
Ain't gonna happen.

mrnickleye · 02-13-2007, 03:37 AM

High NOx is an indication that the EGR system is not working properly. Very possible that the vacuum hoses aren't hooked up properly, or the passages are plugged with carbon, and not allowing exhaust gasses to flow into the intake to control the NOx.

The EGR valves are very tough, and usually don't go bad. They could be plugged up with carbon. The transducer (back-pressure sensor) above the valve does go bad.

You can check some of this out yourself by un-plugging the vacuum hose to the EGR valve while the engine is idling, and use a longer piece of vacuum hose (keep it in your toolbox for future uses) to plug onto the EGR and suck on it with your mouth.

If the EGR valve is working, and the passages aren't plugged, the engine idle will fall right off, and possible kill the motor. If this happens, then your transducer is likely bad. Dealer only part.

If you can't hold the vacuum with your mouth (cause air comes thru) then the valve diaphram is bad, and the valve won't open.

If the idle does not fall off, and the valve seems to hold vacuum, (suck and release quickly with your finger on the valve, you should feel it snap shut), then you can remove the metal tube from the valve to the intake manifold, then try testing again. If you get loud exhaust coming out of the valve, then the passages are plugged in the intake manifold, and must be cleaned out.

The passages may be plugged before the valve, in the EGR cooler. Hope not, as it will be a bitch to remove the cooler and clean it out. Check by removing the EGR valve and starting the motor to hear if exhaust comes out the hole.

mrnickleye · 02-15-2007, 04:22 AM

Here is a blowup of one of the places to clean out some of the carbon build up.

Remove....

http://www.cygnusx1.net/Supra/Librar...re=1703&Page=1

Cover #17864
Clean passages in intake manifold with a coat hanger and carb spray.

http://www.cygnusx1.net/Supra/Librar...re=2501&Page=1

Tube #25601
Cooler #25681 (a real bitch to do)
Valve #25620

Clean holes in head too, you see them in picture...

shiftysupra · 07-04-2008, 09:08 PM

Quote:

Originally Posted by mrnickleye

I'm certain that those people that are doing some intense mods to their engines will be focusing on the best solutions, using 'fuel management' systems, and such, and thus can easily remove the EGR system and have no running problems.

But...to be a guy that opens the hood and rubs his hands together, and says "what can I remove today" ? Well, he just needs to do some research first.

Its like throwing a K&N filter on, and expecting to gain 20hp.
Ain't gonna happen.

Would have to agree here. No point in taking it off unless you have your cooling system upgraded and top notch. Your just putting more stress on your head. If gaining about .1hp means that much to you go ahead and blow a head gasket.

02-15-2007, 04:22 AM	#3
mrnickleye 1000whp postwhore Join Date: Jun 2005 Location: Mojave Desert, Calif. Posts: 1,705	Cleaning Out the Passages Here is a blowup of one of the places to clean out some of the carbon build up. Remove.... http://www.cygnusx1.net/Supra/Librar...re=1703&Page=1 Cover #17864 Clean passages in intake manifold with a coat hanger and carb spray. http://www.cygnusx1.net/Supra/Librar...re=2501&Page=1 Tube #25601 Cooler #25681 (a real bitch to do) Valve #25620 Clean holes in head too, you see them in picture... __________________ Had a Red 1989 N/A. Automatic. Sports Pkg. w/wing. TEMS, and some nice MODS. Sold to a friend 10/08/08. Last edited by mrnickleye; 02-15-2007 at 04:44 AM.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Cold Start System Testing (hard starting)	mrnickleye	MKIII Supra	12	11-13-2010 08:32 PM
Questions about the oem fuel system	Magical Trevor	MKIV FAQ	7	08-19-2007 04:40 PM
tein flex or fuel system	west_side_supra	MKIII Supra	8	04-22-2007 11:01 PM
Cold Air system?	Black'88	Non-Generation Specific Questions	10	04-22-2006 02:40 AM
exhaust system	kewlcoconut	MKIII Supra	10	11-02-2005 07:46 PM

02-07-2007, 06:01 AM	#1
mrnickleye 1000whp postwhore Join Date: Jun 2005 Location: Mojave Desert, Calif. Posts: 1,705	Heavy Modders I'm certain that those people that are doing some intense mods to their engines will be focusing on the best solutions, using 'fuel management' systems, and such, and thus can easily remove the EGR system and have no running problems. But...to be a guy that opens the hood and rubs his hands together, and says "what can I remove today" ? Well, he just needs to do some research first. Its like throwing a K&N filter on, and expecting to gain 20hp. Ain't gonna happen. __________________ Had a Red 1989 N/A. Automatic. Sports Pkg. w/wing. TEMS, and some nice MODS. Sold to a friend 10/08/08.

02-13-2007, 03:37 AM	#2
mrnickleye 1000whp postwhore Join Date: Jun 2005 Location: Mojave Desert, Calif. Posts: 1,705	High NOx & Testing the EGR System High NOx is an indication that the EGR system is not working properly. Very possible that the vacuum hoses aren't hooked up properly, or the passages are plugged with carbon, and not allowing exhaust gasses to flow into the intake to control the NOx. The EGR valves are very tough, and usually don't go bad. They could be plugged up with carbon. The transducer (back-pressure sensor) above the valve does go bad. You can check some of this out yourself by un-plugging the vacuum hose to the EGR valve while the engine is idling, and use a longer piece of vacuum hose (keep it in your toolbox for future uses) to plug onto the EGR and suck on it with your mouth. If the EGR valve is working, and the passages aren't plugged, the engine idle will fall right off, and possible kill the motor. If this happens, then your transducer is likely bad. Dealer only part. If you can't hold the vacuum with your mouth (cause air comes thru) then the valve diaphram is bad, and the valve won't open. If the idle does not fall off, and the valve seems to hold vacuum, (suck and release quickly with your finger on the valve, you should feel it snap shut), then you can remove the metal tube from the valve to the intake manifold, then try testing again. If you get loud exhaust coming out of the valve, then the passages are plugged in the intake manifold, and must be cleaned out. The passages may be plugged before the valve, in the EGR cooler. Hope not, as it will be a bitch to remove the cooler and clean it out. Check by removing the EGR valve and starting the motor to hear if exhaust comes out the hole. __________________ Had a Red 1989 N/A. Automatic. Sports Pkg. w/wing. TEMS, and some nice MODS. Sold to a friend 10/08/08.