Egr help!

[87MK111Supra]

So I rebuilt my engine about 6,000 miles ago and ever since then I've gotten a Code 71. I scraped all of the charcoal buildup all throughout the entire system cleaned all the metal vacuum lines, correctly routed the vaccum lines, and tested every VSV in the EGR system. I also switched out the sensor with a different one. I still get the code. I can't think of any other possible thing that could be setting it off. Do you guys have any ideas or experiences with it? Rob said I could just switch the ECUs to a nonCali but I'd rather try and fix it. It's a California car. Thanks for the help.

 

[toyotanos]

Make sure that the EGR passage in the intake manifold isn't blocked, check the EGR valve's operation/movement, check the modulator valve, and also make sure that the VSV is hooked up right. Those seem to be good starting points. (kinda the whole system, lol)

 

[hvyman]

http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?Section=EC&P=12

edit: wrong link.

 

[mkiiichip]

STEP ONE, make sure you have ported vacuum (like 3-5 in hg off idle) at the egr vacuum ports on the throttle body.
2. make sure you have the same signal at one side of the EGR modulator
3. unplug the larger hose from the bottom of the modulator and make sure exhaust flows through the hose, and flow increases with higher rpm
4. make sure the lower portion of modulator holds vacuum

if all of the above checks out put everything back together

5. unplug the single hose from the side modulator to the EGR valve. check for ported vacuum. (AT THE MODULATOR)
6. again making sure everything is hooked up... unplug the vacuum hose at the egr and make sure you have the same signal as step 5 (your car will have to be at opperating temp for this otherwise the VSV will be open)
6. put 5 inhg vacuum on the egr while running your engine should stumble or die.

hope that helps, post up which step fails


ninja edit for na, but now that i look how do we know were talking about an na?

 

[jdub]

Did you clear your stored codes and recheck?

Did you clean out the port/channel that is inside the plenum? (it leads form the fitting flange to just under the TB)

 

[87MK111Supra]

PrinceChip: Which one? I tried all the ports and have found no vacuum between any of them. Maybe I'm not checking it right.

 

[mkiiichip]

You are going to need a vacuum pump with gauge. Next to impossible to diagnose an egr system without one.

Next thing is i am pretty sure you are not understanding what "ported vacuum" is. both of the vacuum ports at the throttle body (the one for evap and the one for egr) are ported vacuum.

i am going to try and explain ported vacuum. first thing about ported vacuum is there is none with the throttle closed (if you look inside the throttle body you notice that these ports are right next to the tb butterfly, and the ports dont see vacuum until the tb is slightly opened). hook up your vacuum gauge to the rear vacuum port on the throttle body (the one for the egr ), now rev the engine, you should notice your vacuum gauge reads small amounts of vacuum is produced during the early portion of a free rev (note do several saps of the throttle, all the way from a slow rev to a fast snap of the throttle. youll notice that when you do it just right you can clearly see a vacuum signal).. expect to see a minimum of 3 inhg up to maybe 10

the egr works from this ported vacuum signal that gets slightly modified by the modulator.

 

[jetjock]

I'm compelled to point out the TSRM page referenced is for the GTE system. The GE is different.

PC: Well done. If only everything in Tech Sections were as good...

 

[hvyman]

whoops. fixed.

 

[87MK111Supra]

Alright, so I went to test stuff out with a vacuum gauge. I currently have no vacuum at idle but when revved, I get vacuum. I'm not sure what you mean by the same "signal" on each of the sides of the modulator.