dreedraffs Posted February 21, 2006 Share Posted February 21, 2006 My '92 Loyale is missing on power, has rough idle and idle goes up/down when hot. I red a little on the forum and the both TPS and EGR came out as potential problems. I looked at my EGR and the inner is kinda hard to move. Then I realized it been unplugged. So I have what seem to be an unplugged faulty EGR. The car is a winter beater but as I like to work on cars I change small things here and there. I'm wondering what I should do with the EGR valve. Replug it? Change it? Remove it and put a block off plate? Or leave it as it is? Link to comment Share on other sites More sharing options...
subiemech85 Posted February 21, 2006 Share Posted February 21, 2006 use the gasket as a template for when you make the block off plate I used a piece of mower blade engine should be able to run without anything covering the hole gives it a different sound, low power, major vac. leak Link to comment Share on other sites More sharing options...
Subarian Posted February 21, 2006 Share Posted February 21, 2006 You can use a piece of tin from a soup can. It's easiest to block it off where the riser from the exhaust manifold bolts to the EGR valve. Link to comment Share on other sites More sharing options...
idosubaru Posted February 21, 2006 Share Posted February 21, 2006 what does this affect? i'd like to do the same. don't you need to plug the hole in the head as well? does it affect gas mileage? always seemed weird that's it's only on one side of the exhaust? Link to comment Share on other sites More sharing options...
Subarian Posted February 21, 2006 Share Posted February 21, 2006 The principle behind the EGR valve is to introduce an inert gas (exhaust) into the combustion chamber to reduce combustion temps at high engine speed, and thereby reduce formation of oxides of nitrogen. Since it doesn't matter where the exhaust gas comes from, one side of the engine is sufficient. Blocking off the EGR will smooth out your idle (assuming the EGR is leaking) and improve power an mileage slightly. You just need to block the flow of exhaust gases anywhere in the system. On the EA82, it's easiest to do it where at the flange where the riser from the head meets the EGR valve. Link to comment Share on other sites More sharing options...
idosubaru Posted February 21, 2006 Share Posted February 21, 2006 The principle behind the EGR valve is to introduce an inert gas (exhaust) into the combustion chamber to reduce combustion temps how does exhaust gas reduce temps? the exhaust is post-combustion hot stuff right? will blocking a working EGR valve (not leaking) affect mileage at all? Link to comment Share on other sites More sharing options...
Subarian Posted February 21, 2006 Share Posted February 21, 2006 It reduces combustion by introducing a gas that won't burn (since it's already burned). It's really not about the temperature of the gases; it's about the combustibility. You might notice a slight improvement in mileage and power, even if your EGR is working as intended. The nice thing about a fix like blocking off the EGR where I mentioned earlier is that it's easily reversed if you decide you don't like it. Just pull the piece of metal out, and your EGR is functioning again. Link to comment Share on other sites More sharing options...
moshem74 Posted February 21, 2006 Share Posted February 21, 2006 what do you mean like it or not? does it improve power or not? if yes...i'll block it also. Link to comment Share on other sites More sharing options...
Subarian Posted February 21, 2006 Share Posted February 21, 2006 I can't imagine why you wouldn't want to keep it blocked off. I'm just saying it's reversible if you decide you need it (like for an emissions test). You will get a little more power. It's pretty simple; instead of introducing a gas to quench the burn in the combustion chamber, you're letting it burn. More burn = more power. Link to comment Share on other sites More sharing options...
naru Posted February 21, 2006 Share Posted February 21, 2006 It reduces combustion by introducing a gas that won't burn (since it's already burned). It's really not about the temperature of the gases; it's about the combustibility. Well not really.EGR works because of the high specific heat of the newly created water in the exhaust gases.The specific heat of the EGR is much higher than fresh air, hence EGR increases the heat capacity (specific heat) of the intake charge, thus decreasing the temperature rise for the same heat release in the combustion chamber. You might notice a slight improvement in mileage and power, even if your EGR is working as intended. The nice thing about a fix like blocking off the EGR where I mentioned earlier is that it's easily reversed if you decide you don't like it. Just pull the piece of metal out, and your EGR is functioning again. Disabling a functional EGR is a DUMB idea.Among other problems,gas mileage and power will go DOWN because of engine throttling losses at cruise. Link to comment Share on other sites More sharing options...
WoodsWagon Posted February 21, 2006 Share Posted February 21, 2006 Another thing to consider: High combustion temps = susceptability to detonation. While you have a larger mixture charge in the cylinder, you also have more detonation, so It's a mixed bag. NOx is also a major smog pollutant. It reacts with the sunlight to make smog. If you care about that though. Many EJ22's never came with EGR. Not having the hose hooked up to the valve will create a vacuum leak, so you might want to plug the vacuum hose. Leaving the hose plugged will deactivate the EGR valve and work the same as a cover plate. If you have smog police, put a BB in the vacuum line, then reattach it. The bb will invisably block the vaccum flow, and everything looks like it is still properly hooked up. Link to comment Share on other sites More sharing options...
Subarian Posted February 22, 2006 Share Posted February 22, 2006 Disabling a functional EGR is a DUMB idea.Among other problems,gas mileage and power will go DOWN because of engine throttling losses at cruise. Dumb is in the eye of the beholder, I guess. I blocked mine and picked up smoother idle, better acceleration, and about 1 MPG. So there's your DUMB theory put into practice. As far as disconnecting the EGR vacuum line, it won't accomplish anything with a malfunctioning EGR. And I've never experienced any detonation issues. And BTW, my sube passes emissions tests just fine. It's all in how good you are at tuning an engine. Link to comment Share on other sites More sharing options...
naru Posted February 22, 2006 Share Posted February 22, 2006 Dumb is in the eye of the beholder, I guess. I blocked mine and picked up smoother idle, better acceleration, and about 1 MPG. So there's your DUMB theory put into practice. That`s because your EGR was faulty.The EGR valve is closed at idle and has no effect whatsoever.Either the valve was leaking at idle,the diaphram was ruptered creating a vacuum leak or the throttle was mis-adjusted. As far as disconnecting the EGR vacuum line, it won't accomplish anything with a malfunctioning EGR. That depends what the malfunction is. And I've never experienced any detonation issues. And BTW, my sube passes emissions tests just fine. It's all in how good you are at tuning an engine. But you are still emitting more NOx and burning more gas for no gain. Link to comment Share on other sites More sharing options...
Subarian Posted February 22, 2006 Share Posted February 22, 2006 But you are still emitting more NOx and burning more gas for no gain. Reread my last post. Power increased, fuel mileage improved (better mileage=less fuel burned). I would call both of those a gain. And I'm still passing emissions with no problem. Link to comment Share on other sites More sharing options...
naru Posted February 22, 2006 Share Posted February 22, 2006 Reread my last post. Power increased, fuel mileage improved (better mileage=less fuel burned). I would call both of those a gain. And I'm still passing emissions with no problem. Totally believable for a leaky EGR.I meant no gain from disabling a working one. Link to comment Share on other sites More sharing options...
torxxx Posted February 22, 2006 Share Posted February 22, 2006 you guys do that on a SPFI or a carb'd engine? I'd like to get rid of mine, just because I ripped out all the other emissions crap they crammed onto these engines. Link to comment Share on other sites More sharing options...
moshem74 Posted February 22, 2006 Share Posted February 22, 2006 hi can you please discribe what part exacly did you blocked , what part did you took out...? i want to try it. thank you. Link to comment Share on other sites More sharing options...
stephenw22 Posted February 22, 2006 Share Posted February 22, 2006 From the placement of the EGR valve, it would seem to me that most of the recirculated exhaust would end up in the passenger side cylinders. Wouldn't that lead to problems with a/f ratio and combustion temps between the heads? At any rate, I blocked off my EGR system and removed all the piping. I did it mainly to simplify the engine layout under the hood. I didn't notice any difference in mileage or performance, and yes, the EGR system was functioning properly when it was removed. Maybe on a new car it would make a difference, but on these oldies, I'd doubt it. Link to comment Share on other sites More sharing options...
bgd73 Posted February 22, 2006 Share Posted February 22, 2006 A functioning EGR on a soob 1.8 is a bad one, regardless of mileage. If car has low mileage, what gets recycled is even hotter(clean burn is a very hot fast one), as miles increase, it turns to a dirty engine killer, and hangs on to inefficient heat going through intake, longer with deposits built up. After blocking off with home-made metal gasket, it still stays hot towards intake like a copper pipe heatsink, use the thickest piece of aluminum you can handle to put in between for gasket, it helps a bit more ... Fuel mileage most definately goes up, as well as thermal ambience where an engine really needs it to be cool,before combustion chambers rapid expansion ,the intake.(more cool air, more compression due to expansion, cleaner burn... Why EGR at all ????) Not to mention, anyone notice the flow is upside down on a boxer? heat is forced down, you gain this flow correctly, its just like having a different engine from start to cruising. Link to comment Share on other sites More sharing options...
85Sub4WD Posted February 22, 2006 Share Posted February 22, 2006 From the placement of the EGR valve, it would seem to me that most of the recirculated exhaust would end up in the passenger side cylinders. Wouldn't that lead to problems with a/f ratio and combustion temps between the heads not really, because the input port is extremely close to the base of the TB I have run with a working EGR, and with a blocked EGR - !!NO MAJOR DIFFERENCE!! - because I try to be environmentally conscious, I leave mine working - I think my fuel economy is slightly better with the working EGR, and the engine seems smoother - some cars (particularly Datsuns) had EGRs before they were required for emissions reasons because of improved driveability and fuel economy; the only reason you would get improved fuel mileage by disableing one is if the EGR system was not running properly in the first place you are welcome to debate all you want, and if you use the search function, you will find many MORE debates on this subject, bottom line is that it is a matter of personal pereference. the egr valves can generally be cleaned (proceedure is covered in FSM, or any aftermarket manual), and therefore are supposed to have an indefinate service life. My vote is to fix it and leave it connected, partially because the computer does funky stuff when you mess around with sensors & such. Link to comment Share on other sites More sharing options...
thealleyboy Posted February 22, 2006 Share Posted February 22, 2006 I can't speak for FI vehicles, but eliminating the EGR (and other emissions crap) on a carbed intake didn't seem to hurt anything - and possibly improved performance a little. I fabricated block-offs using thick stainless steel electrical "blank" plates. Worked great and very inexpensive. As far as the necessity for emissions systems, remember, most of these were "add-on systems", adapted to motors that were engineered before the era of emission controls. Eliminating something that was added on, brings you back to square one. Fuel injection may be a little trickier, as this system is much more dependant upon the ECU, sensors etc. I would definitely study, and understand the system thouroughly before starting to disable anti-smog devices. However once again, if you remove a system in it's entirety, you should be back to "sqaure one". good luck, John Link to comment Share on other sites More sharing options...
bgd73 Posted February 22, 2006 Share Posted February 22, 2006 85sub4wd: No major difference needs a cold air intake, it is, dare i say.. Phenomenal. got 90hp? Link to comment Share on other sites More sharing options...
85Sub4WD Posted February 22, 2006 Share Posted February 22, 2006 85sub4wd: No major difference needs a cold air intake, it is, dare i say.. Phenomenal. got 90hp? what you fail to realize is that by the time it actually reaches the intake, the exhaust gas isn't that hot - granted it is still over 100F, but I got nothing over 120F using a laser thermometer on the body (better than 1% accuracy) - in terms of temp, it is pretty insignificant when you consiter you ambient around here is ~70F - not to mention the fact that the EGR's oriface is a precision aperature, intended to allow a specific (and small) amount of air in - not to mention the fact that it prolongs engine life by decreasing the combustion chamber temperature - as I said, a properly functioning EGR will not hurt performance, say what you will, but I've got the #'s and expierence to prove my point; not to mention the automotive engineering design theories behind the principle (theory + proven theory = fact) I converted my car to SPFI from Carb - I kinda have a good idea as to how the FI system works, seeing as how I had to install it all from scratch - and I am definately making the 90+ hp of the SPFI system (from the 82 of carb), b/c I have done other stuff as well, I have been working on that engine since I was in 5th grade, I know how to service it properly the only time intake temp is really an issue is with turbocharging, hence the principal behind the intercooler, but the turbo bodies get to MUCH higher temps, and ALL the intake air goes through them BTW, the egr valve shuts exhaust flow by sticking a metal plunger down into the exhaust gas passageway, sealing it off, if you just put a metal plate over where the EGR valve is supposed to go an don't put an indentation or something to cutoff air flow, you are essientially causing a stuck-open EGR valve condition, rather than blocking it off if you have dismantled the valve, you know what I am talking about - easiest way to deactivate the EGR system is to disconenct the vacuum hose to the valve, and plug the vac hose with a BB or something creative Link to comment Share on other sites More sharing options...
torxxx Posted February 22, 2006 Share Posted February 22, 2006 ok, so I dont need a block off plate then? I'll just put a vac cap over the line to the valve and where it comes out of the intake? Link to comment Share on other sites More sharing options...
Subarian Posted February 22, 2006 Share Posted February 22, 2006 The easiest way on an EA82 is to block the exhaust port before it gets into the EGR. Subaru made it incredibly simple. Find the elbow that goes from your passenger side head to the intake manifold. You'll find it under a small elbow-shaped heat sheild. There are two bolts that connect the elbow to the manifold (arrows in picture). Put a piece of tin from a soup can behind that, and there's no exhaust flow to the intake or the EGR valve. Link to comment Share on other sites More sharing options...
Recommended Posts
Please sign in to comment
You will be able to leave a comment after signing in
Sign In Now