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| EGR Valve on 2.8 V6 question (Page 2/5) |
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Patrick
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DEC 16, 05:37 PM
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| quote | Originally posted by ZaraSpOOk:
there is no sensor on the EGR circuit for the ECM to know whether the circuit is functioning properly or not
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I guess a Code 32 appears through magic of some sort. 
True, the ECU has no direct knowledge if the EGR valve itself is operating properly... but a non-functional EGR solenoid will trip the code.
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ltlfrari
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DEC 16, 06:01 PM
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When the ECM opens the EGR, the recirculated exhaust gasses should cause a change in the exhaust gasses going down the ex pipe. That causes a change in the O2 sensor output which is what the ECM is monitoring. If the ECM does not see a corresponding change in the O2 reading when it actives the EGR solenoid, it raises the code and turns on the check wallet light.
On a side note. Can that GA 7730 ECM/digital egr valve mod be used on a manual trans car ?------------------
Anything I might say is probably worth what you paid for it, so treat it accordingly!
Dave
www.ltlfrari.com
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fierofool
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DEC 16, 06:21 PM
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The digital EGR adapter kit can be used on any V6 Fiero that uses the stock crossover pipe.
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TM_Fiero
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DEC 16, 06:32 PM
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Does the digital EGR work with the original ECM or only with the 7730?
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ZaraSpOOk
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DEC 16, 07:48 PM
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| quote | Originally posted by Patrick:
I guess a Code 32 appears through magic of some sort.
True, the ECU has no direct knowledge if the EGR valve itself is operating properly... but a non-functional EGR solenoid will trip the code. |
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but the ECM still does not know if the EGR valve is working, whether the EGR tube is connected to the intake manifold, IOW, if what you say is true, the ECM only knows that the solenoid is working, not whether NO2 is being redircted to the intake manifold as the EGR system is supposed to do
as the system redirects a very small amount of NO2 to the intake manifold it is highly unlikely the O2 sensor can tell if the EGR system is working
the O2 sensor reports the oxygen level, not the NO2 level
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ZaraSpOOk
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DEC 16, 07:54 PM
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| quote | Originally posted by ltlfrari:
When the ECM opens the EGR, the recirculated exhaust gasses should cause a change in the exhaust gasses going down the ex pipe. That causes a change in the O2 sensor output which is what the ECM is monitoring. If the ECM does not see a corresponding change in the O2 reading when it actives the EGR solenoid, it raises the code and turns on the check wallet light.
On a side note. Can that GA 7730 ECM/digital egr valve mod be used on a manual trans car ?
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so explain why my vehicle didn't throw a code
it was about as non functional as can be
EGR vavle not working due to broken vacuum tube
EGR tube to manifold broken
entry to manifold clogged
engine ran fine, no change in gas mieage or performance, made no difference except likely in NO2 levels
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Patrick
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DEC 16, 08:08 PM
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| quote | Originally posted by ZaraSpOOk:
And when you consider the recent forest fires out west, the emissions given off by my car which is only driven about 2 or 3 thousand miles is insignificant.
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It's obvious (from your rationalizations, such as above's) that you had already decided before posting here to delete your EGR. I'm not sure what the purpose of this thread is, other than for you to rebuke whatever anyone says.[This message has been edited by Patrick (edited 12-16-2020).]
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fierofool
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DEC 16, 10:13 PM
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| quote | Originally posted by TM_Fiero:
Does the digital EGR work with the original ECM or only with the 7730?
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I believe it will work with a reprogrammed Fiero ECM. A long time ago we had a member with an 85GT that did the EGR conversion and as I recall, he used the original ECM. Sinister Performance can give you a definite answer as he would be the one who developed the adapter and does reprogramming of ECM's for the conversion.
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ZaraSpOOk
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DEC 17, 04:19 PM
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| quote | Originally posted by Patrick:
It's obvious (from your rationalizations, such as above's) that you had already decided before posting here to delete your EGR. I'm not sure what the purpose of this thread is, other than for you to rebuke whatever anyone says.
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no, I'm trying to get information to avoid possible problems.
I do not have the section on drivability for the 2.8 V6 in my service manual, it only includes the 2.5, so hearing that the ECM monitors the relay is news to me, but that still doesn't mean the ECM knows the EGR is doing what it is supposed to do, that could only be done with a sensor where the air from the EGR circuit enters the manifold (or something similar)
the O2 sensor only sends a voltage to the ECM, and the ECM interprets that as the amount of oxygen, there would be no way of knowing what the EGR circuit is doing from the O2 sensor
if you have a problem with the discussion you shouldn't be here, your above comment serves no purpose, in fact only a negative purpose IMO
yes, I already made up my mind to delete the EGR circuit, I was wondering if anyone experienced any problems doing so, if they want to do it in a different manner, that is their choice, as I mentioned previously, I will post the result here of doing it my way
the EGR is closed at idle or cruising for the most part, so putting a plate on the manifold to shut off the entrance of exhaust gasses will prevent any problems in that case, what I am wondering is if anybody has experienced problems in NOT having the EGR circuit open under acceleration, which is primarily when it is open
even if they had I might still do it, since I'm not a racer wanna be, I just use the vehicle to go from point A to point B, hard acceleration is seldom used, when I want to drive like that I have a different car
BTW, I am also closing off the EGR port on the Y pipe with a metal plate, no point in having it there when it isn't serving any purpose, and IMO it wouldn't be a good idea to leave the possibility of it opening
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Dennis LaGrua
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DEC 17, 05:17 PM
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The EGR function blows a bit of dirty carbon filled exhaust smoke into the intake manifold. The EGR system reduces NOx through lowering the oxygen concentration in the combustion chamber. It also allows the engine to run leaner without burning a piston under certain conditions thereby increasing gas mileage a bit..
On a hobby/classic/collector car I prefer to run without it ( or use a restriction washer) but on a daily driver I would keep it as it does serve a purpose. In many states you will not pass inspection without it.
Having said that the EGR solenoid function, not the EGR valve itself, is what the Fiero ECM expects to see. Without the solenoid a code will be set. Some ECM program reprogramming is necessary to delete the code and to adjust the fueling tables to see that a piston is not burned. ------------------
" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "
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