I am considering going without it. I do not need to license my car each year since it is registered as a classic, so even if some day they bring back emissions testing, It will not have to go through testing. 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. As you can see from the picture, it wasn't doing anything anyway, both whatever that black line did, it was broken, and the EGR connection to the intake manifold was broken. Looking at the input to the manifold it is all clogged up, so no air gets in anyway. If I do go without I should probably make sure the manifold connection is closed rather than depend on the clog to stay that way. The car seems to run fine without any negative consequences. Has anybody else done this? What was the result?
Thanks for the link, but I am wondering the value of the info, the ECM does not control or monitor the EGR and I don't see the value in cutting out the vacuum to the EGR if it isn't installed or isn't working
But the car’s computer does control the EGR and throws a Check Engine light when it isn’t working. There is (supposed to be) a solenoid on the other/passenger side of the Engine that controls when the EGR opens and closes using vacuum lines. There is a big hard vacuum line that traverses the plenum from the solenoid to the EGR valve. The ECU controls this solenoid, so it is important to modify your ECU chip to keep it from throwing a check engine light and so your car runs better on the highway.
I think just unplugging the solenoid stops the CEL (?) BUT the ECU still runs the engine like the EGR is working and there are issues that result from that, especially with highway driving.
Most EGR solenoids are gummed up, the plastic is crumbling from engine heat, and the internals are all oxidized from weather. As you’ve already seen, most EGR valves are also in terrible shape. Valves are cheap but It is literally impossible to buy new EGR solenoids in 2020. There was a cruel joke of an eBay listing last year that had a NOS solenoid listed for like $600.
From what I’ve read on the forum the only viable long term solutions to fixing your EGR now is to get lucky and find a low mile solenoid and deoxidize and weatherproof it,
OR
swap in a newer 7730 ECU, have a custom chip made that runs the 2.8, get a new custom made EGR valve adapter plate (which from what I’ve read just had its last production run) and use an electronic EGR valve in place of the old vacuum valve.
Sure, delete the EGR but do it right and get the modified ECU chip.
Also, It’s far more damaging to the environment to throw another Fiero in a crusher and build a new car (do you know how much permanent environmental damage occurs mining crap for Tesla batteries?), than keeping a Fiero on the road without an EGR.
[This message has been edited by wwcvel (edited 12-13-2020).]
swap in a newer 7730 ECU, have a custom chip made that runs the 2.8, get a new custom made EGR valve adapter plate (which from what I’ve read just had its last production run) and use an electronic EGR valve in place of the old vacuum valve.
Sure, delete the EGR but do it right and get the modified ECU chip. ......................snip.........................
We still have 9 Digital EGR Adapter Kits on hand. We have reduced the number being produced with each new production run due to the reduced demand.
But the car’s computer does control the EGR and throws a Check Engine light when it isn’t working.
yes, the ECM does tell the EGR when to open and close, but beyond that no, It has no way of knowing whether the EGR actually opens and closes,. How do I know that? the service manual says so plus, if you look at the pic I posted, the vacuum line is broke, and the tube from the EGR was broke as well PLUS, the opening in the manifold was all gummed up with carbon and no check engine light that's because the ECM doesn't monitor it
I closed the opening to the manifold with an aluminum plate as far as the solenoid is concerned, the vacuum line is closed as well where it is broken, the ECM can "tell" the EGR to open and close all day and it isn't gonna know what it is doing BTW, it is closed at idle, open at pretty much all other times
I'll report back if there is any trouble with what I have done but thanks for everyone's response
[This message has been edited by ZaraSpOOk (edited 12-14-2020).]
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!
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.
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
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 ?
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
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.
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).]
Does the digital EGR work with the original ECM or only with the 7730?
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.
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.
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
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 "
yes, I already made up my mind to delete the EGR circuit
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
When you consider the current pandemic situation worldwide, the "negative purpose" of my above comment in an obscure car forum is insignificant.
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.
Why don't you do the responsible thing and repair the EGR system on your car instead of doing a hack "delete" job.
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.
LOL, that's one way of stating it. You seem to be one of the few here who know what you are talking about, so why do you run without on a hobby/classic/collector car but keep on a Daily driver? I think I know, but I think it would be helpfull for others to hear from somebody that knows what they are talking about. Plus confirm what I think I know.
That last underline is what really motivated this thread, if adjusting fuel table is really neccessary. It sounds like many have deleted the EGR circuit, and at least nobody yet has experienced negative consequence.
BTW, once I get my Fiero back on the road and we can cross the Canada border I plan on touring BC with my Fiero.
I don't really see how you're going to hole a piston cruising along at low loads (low heat). Plus you have oxygen sensor feedback to correct things.
You should your computer retuned because it is expecting EGR flow, but none occurs. So there may be a hiccup as the injected fuel quantity is wrong for the true amount of fresh air in the intake manifold.
It might work okay with the stock computer chip, but if you're the "crossing the Ts and dotting the Is" kind of guy, and you want the best driveability, you get a guy like Darth Fiero to send you a customized chip, which you plug into your computer.
EGR is not necessary for engine operation. Many engines have been built without it. It is an anti-pollution feature.
EGR is not necessary for engine operation. Many engines have been built without it. It is an anti-pollution feature.
I don't believe there was any doubt expressed by anyone about that.
On a properly running engine, EGR operation has no discernible effect on performance. And as a side effect of pollution reduction, fuel economy is actually slightly increased. Seems like a fully functional EGR is a win-win situation... but everyone makes their own choices.
As I stated I am not a proponent of the EGR function but it serves a purpose in lowering NOx emissions but more importantly it lowers combustion temperatures that may over time burn a piston . I run without it on my classic/hobby/collector cars only because I drive them only a couple of thousand miles per year, the system is unsightly and they are registered as "historic". They are also tuned accordingly to avoid the lean burn condition that is used under EGR activation cycles and for power. On my street vehicles that are daily driven so I don't see much value in re-tuning and adding to air pollution, plus I like to maximize on gas mileage. In NJ ( as in your state) we also have mandatory vehicle emissions inspection on cars newer than 25 years old and you will not pass without the EGR system hooked up and functioning. Being stopped for running daily drivers without pollution equipment will result in a very serious fine. You cannot even idle your car for more than 3 minutes in this state without breaking the law.
------------------ " 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 "
85 GT. Used to fail smog years ago in LA code 32 -EGR. Don't remember replacing it, but did replace the solid tube and paid ?$90 for the flex stainless which I am still running. It no longer sets 32, but I did a smoke test and found a vac leak in/around the EGR. Careful regasketing helped ,but still hissing. Also once I recall disconnecting briefly and experienced spark rattle which disappeared once EGR was reconnected. Never searched out a solenoid. The smoke seems to be coming from below the diaphragm which itself holds perfectly when tested with a gauge. Rock shows the EGR "commmon" to early NIssan 620, B 210. BTW Calif wanted all Fieros off the road decades ago stating to me "pattern failures." Still a rewarding DD .
I am interested in this thread and any additional feedback / comments. For the simple reason that the Fiero I bought a bit over a year ago has no crossover tube to the intake manifold and the exhaust port for the EGR valve is welded shut. There is no vaccum line connected to the EGR valve either.
There was no check engine light and drove the car 90 min home with no issues. I usually like to return everything to stock but with what has been done to the car already makes it relatively expensive to get it back to stock.
So not to highjack the thread, but just like the OP , I would be interested in any other feedback and who no longer uses an EGR and if they had any check engine light issues.
So not to highjack the thread, but just like the OP , I would be interested in any other feedback and who no longer uses an EGR and if they had any check engine light issues.
Whether or not the CEL comes on isn't the issue. You need to determine if your PROM/ECU has been reprogrammed to run without a functional EGR. If it hasn't, you run the risk of damaging your engine. Lack of a CEL does not indicate that your engine is operating safely without an EGR.
[This message has been edited by Patrick (edited 12-25-2020).]
Hmm, thanks for the feedback. What would be the basis for damaging an engine by not running a functioning EGR valve and not reprogramming the prom?
quote
Originally posted by Patrick:
Whether or not the CEL comes on isn't the issue. You need to determine if your PROM/ECU has been reprogrammed to run without a functional EGR. If it hasn't, you run the risk of damaging your engine. Lack of a CEL does not indicate that your engine is operating safely without an EGR.
Answering my own post....with a bit of Google research, the EGR valve reduces combustion chamber temperatures. So without it that can cause pinging or detonation which can cause engine damage. I assume the reprogramming of the prom takes that into account.
quote
Originally posted by nero:
Hmm, thanks for the feedback. What would be the basis for damaging an engine by not running a functioning EGR valve and not reprogramming the prom?
From my understanding, an EGR allows the engine to run leaner than "normal" while cruising (without issues) which is why emissions are lowered and MPG is improved. However, if the EGR is disabled and the PROM/ECU is not reprogrammed to compensate, this lean condition can lead to excessively hot (damaging) combustion chamber temperatures.
[This message has been edited by Patrick (edited 12-26-2020).]
Yep, that is my understanding now as well. So simple solution......go from idle to wide open all the time and there are no potential issues........lol.
I also read that running premium fuel (higher octane) is suggested to help prevent any pinging due to the higher combustion temperatures.
I guess I have more parts to add to my list. Good thing I do not keep track of what I spend on it. But its a red(ish) gt so I should be able to get between 70000 and 90000 based on recent sales.......
you are free to believe whomever you like, but you should research this further
I have run mine for at least 10K miles with a non working EGR without incident. But then I mostly just putt around in mine, I have no illusions of being the fastest guy on the road in my Fiero. I have another car when I want to do that.
the service manual states under load/acceleration is when you are in danger of running too hot with a faulty EGR the EGR circuit is not much of a factor when cruising, and essentially zero at idle (or should be if it is working correctly)
but again, you are free to believe what you want
When I asked if there were any problems experienced with eliminating the EGR, people seem to think that throwing a code is a problem. A code is merely a notification that an input to the ECM is out of range, it may or may not be a problem. Only further investigation will determine if it is actually a real problem. Throwing a code is a symptom that something MAY be a problem. Do you see the difference between a problem and a symptom? Note that my EGR system was about as broken as it can be, the only thing that works is the relay, hence no code thrown So tell me a code indicates a problem. I repeat, a code only indicates some input to the ECM was out of range. I recall my Mazda would turn on the “Service Engine” light at 70,000 miles and multiples thereof regardless how the engine was running. I ran it from 140,000 miles (when the light dutifully came on again) till 210,000 miles when the “service engine” light turned off! Apparently it was just a toggle. My 2003 Toyota had a blown head gasket and I fixed it and subsequently a code was thrown indicating an oxygen sensor problem. No, they are working correctly, and have been for the last 60,000 miles. Every once in a while I turn off the the “service engine” light but I'm not going to invest time and money to stop it from throwing a code, not on a vehicle that has over a quarter million miles with one wheel in the junk yard. It is my beater. Having driven it for as long as I have I know when it is running correctly and when it isn't, I don't need a code to tell me that, although I do appreciate the code to help me isolate the problem when it isn't running correctly. If you disagree, that is your right, I'm not trying to convince you otherwise. If you want to spend time and money fretting about a code, knock yourself out, have at it, enjoy! Go ahead and respond telling me I'm wrong and a fool if you like (hopefully you won't be too offended I ignore your opinion). This is the second time in the 30+ years I've owned this Fiero I've dropped the cradle to fix that “highly desirable” Getrag (LOL). There was no code to tell me it needed repair, nor does an absense of a code indicate it is running correctly.
Yep, I am in 100% agreement with what you have said based on what I have read / understand. Any 'potential' damage would be under load. So if you do highway driving or even back road cruises with any kind of inclines even at modest speeds, that would be considered under load. Best way to test for pining or detonation is at modest highway speed slightly dipping into the throttle to maintain speed going up an incline.
As for actually causing damage to the engine, I have no idea at what point or how long it would take etc etc or if it would even happen and would not even want to guess. As you said, depends who you listen to, what you read, there appears to be many opinions and different situations. All I would comment is engineers design a car to work at specific min / max ranges. Making changes that cause the car to go outside those min max ranges without compensating for them in some way means you do take some risk in terms of potentially impacting how the car performs or potentially reducing the life of a component or damaging a component.
So has everybody serviced their EGR system every 30K miles? my Fiero is coming up on 88K miles, so I should have done it at 30K & 60K When my car turned 30K I looked at servicing it and said screw that.
Servicing in my case now, since it is getting close to the third time it should be serviced was getting rid of it and putting a plate over the opening in the manifold. Even that was difficult with the engine out of the car, the bolts are upside down and tucked away. (IOW, standard operating procedure for a Fiero, LOL)
I'd say there is a fair chance over 95% of Fiero's have not had their EGR system serviced every 30K miles. It's probably closer to 100%. It doesn't seem to me that 2.8 V-6's have had a bad record for pistons burning, so I am going to say it is extremely rare, if it happens at all.
If the manual isn't enough to convince you it is mostly in use under load, common sense should have told you "when is temperature highest?" when you are stomping on the accelerator is the common sense answer (just when you want exhaust gas added to your intake manifold right? LOL)
BTW, I have my Fiero back together, it was is snowing and I've never even driven it in winter, so I ran it in the garage to get the temp up and make sure the collant level is correct.
No check engine light, so apparently my EGR relay is working (lol) although who knows, maybe the ECM isn't working properly
[This message has been edited by ZaraSpOOk (edited 12-29-2020).]
I've never serviced my EGR systems until I get a warning light. If the system is working properly, there's really nothing to service. Replace the valve when it goes bad. Replace the solenoid when it goes bad. Replace the EGR tube when you can't find the cause of the high idle.
I've usually had more than 1 Fiero at a time. My current 2nd is mainly used for running around town. Low speeds and stop and go. I had a bad solenoid but the light never came on until I would take it out on the major roads on the way to a club meeting or just to get the cobwebs out. Then the light would come on. Usually when I drove for a bit over 50-55 mph. I drove it that way for a while until I found a replacement solenoid and then no more warning light on the highway.
Update for those retaining 85 GT EGR valve. Scored NOS AC Delco at half price with washers. Original removed CFX 17085897 . Received 2149045 with 9 calibrated washers ranging .145" - .354 " Put in .354" Had a vacuum hiss and expected to pull intake until smoke test said EGR valve. The removed unit had the "pintle" style moving valve which I could not measure . The removed valve was apparently not sealing when closed ( idle OK) and hissed very loudly under low throttle. (I did see a "help me" thread unanswered to that subject-hope he sees this). I chased this noise a long time . It was so loud when driving I suspected break in vac feed to brake. BTW Rock Auto's Delco data "same as " lists the removed pn , but the 17085987 does not appear on the washer list I got even though the .354" is present (close to the .342" recommended this thread'
Ebay search word Datsun 210 EGR valve, "alpinejohn" WI
[This message has been edited by hobbywrench (edited 01-03-2021).]
