V6Discussion and questions about the base carbureted or MPFI V6's and the rare SFI Turbo V6.
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I'm trying to figure out why I'm getting crappy gas mileage, and next on my list is a bad egr. If I unplug it, it should disable it right? I know I'll get the SES light, but will that make the gas mileage better, assuming the egr is bad? I'm trying to figure out if its bad without replacing it.
Car's a 91 3.1 if that helps.
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__________________ -Mitch
Last edited by Orinackra; 10-05-2003 at 01:43 AM.
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i have a 91 3.1 and i am running no egr. i get a code/light occasionally but not real often. i don't remember having a gasket either. i also have the digital egr that came off of my car...
Considering the cost to get a new one, I think I may try and clean the one I have. And get a gasket for the stupid thing. Getting the chip redone seems too much of a pain. Thanks guys!
I think mines starting to act up, the idle is occationally starting to bobble sometimes and has died twice at lights the past week. A bad EGR will sometimes stay open at idle- not suppose to open at all until cruizing speed are reached.
you might want to look to actually fixing the EGR, bypassing it isn't really good for performance. When you're at highway speeds cruising, the EGR is supposed open, cooling down the combustion chambers so the ECM can advance the timing. When the EGR doesn't open, and the ECM advances the timing, the engine gets close to spark knocking. the knock sensor senses this, and slams the timing back down. So if you bypass the EGR you're basically driving down the highway with your timing jumping back and forth, which isn't good for performance or gas mileage.
I hear that, my gas mileage is around 13mpg, and the only things I can think of left to check are timing(cause I don't have a light yet), egr(cause I don't want to pay to replace it) and a bad cylinder. I've replaced every gasket, every vacuum line, plugs, wires, cap, rotor, o2 sensor, oil, coolant, and my mileage absolutely won't change.
I did pull my egr off yesterday, and it does have alot of carbon build up on it, so it couldn't hurt to clean it I guess.
Actually, I have till the end of the week to figure it out, cause then I'm buying a 4 banger Sunbird as a daily driver, so the Firebird gets to sleep in the garage for awhile.
I have heard the same thing about EGR, but I have never seen any detrimental effect from removing it. Since yours is an expensive one to replace anyway, it can't hurt to try. Just make a blockoff plate out of flat steel, and seal it up. You can fool the computer with a resistor in the EGR solenoid wiring if necessary (did that on my 97 SS, even with the original OBDII computer it never coded), but Redraif's 87 never coded with the EGR blocked off and removed.
__________________ 1981 Corvette LSX/T56 Project
1987 Trans Am
1985 Trans Am
1997 Camaro SS #359 383 LT1 - Sold 8/12/09
Originally posted by Gumby I tried the EGR bypass/block off plate thingy. I found the car had a better idle but it seamed to lack when ya was really gettin on it.
Matt[/url]
Don't know why that would be- you do know that the EGR shuts down at full throttle don't you- You had something else wrong with your car.
LT1guy, My '87 has never thrown an EGR code in all the years I have owned it- Have had many a bad EGR.
Originally posted by AGood2.8 Don't know why that would be- you do know that the EGR shuts down at full throttle don't you- You had something else wrong with your car.
LT1guy, My '87 has never thrown an EGR code in all the years I have owned it- Have had many a bad EGR.
(LT1Guy replying on Redraif's computer)
Thats weird...Redraifs had coded for EGR before, but hasn't in a long time (since we initially blocked it off about a year ago). Some cars will code if the electronic side isn't working, and since he said he had a 91 (with the electronic EGR) I thought it may be a possibility. I could be wrong though, I have enver owned/worked on a 91 V6.
Originally posted by Mitch DoGG I think I am gonna try and make a bock off plate. It can't hurt. I'm already going through a quarter tank of gas a day, it can't get much worse.
If you have the digital EGR valve, leave it connected to the wiring harness after you remove the valve and plate the intake, the computer will not know that it is unhooked, this may keep you from getting a code. It worked on my ratty old work car, but then it looks ugly having the damn thing strapped to the intake with a wire tie! lol!
But it can help you figure out if the EGR valve is blowing by or not.
Keep in mind that if you have to smog test you'll have to fix it. I was told the EGR valve's main job is to reduce the NoX output in the exhaust, so not only would it fail the visual, but the sniffer too.
Not necessarily...Redraif passed her last test with no problems, and the EGR was blocked off. Thats on a car with lots of engine mods too. My 97SS also passed with no EGR or smog pump, and that too was on a heads/cam car.
If you just block off the EGR, you should pass tailpipe and visual. If you remove the electronics (I used a resistor in the connector on my LT1), it'll still pass the tailpipe but not a visual (they don't worry about a visual here, as long as you have cats).
fix the gasket. keep the egr or replace it, it will pay for itself.
when my gas milage goes down the first thing I check is my egr gasket. Use a piece of heater hose as stethescope on the egr base, if you hear any ticking, fix it. None of the gaskets available fit, not even the ones that came with the complete gasket set. I have to make mine. The first few tries I cut them out of exh manifold gaskets, that lasts about 1500km depending on how often I redline it. Last few times I used a black cardboard gasket out of a set for a ford 302 and JB weld, that lasts 3000km. Typicaly gas milage goes down to 18-20 from 28mpg.
When my car got warm it would stall out at stops.
Then I unplugged the digital 3.1 EGR in my 1990 Pontiac Firebird and the stalling stopped but i think I'm getting bad gas mileage{ and}
My 90 3.1 got a block of plate and then I mounted the slightly modified EGR back in it's original location. It passed visual and sniffer in CA. It also improved the idle and gas mileage.
__________________ "Towering genius disdains a beaten path. It seeks regions hitherto unexplored."
--Abraham Lincoln
I have had the working EGR off my car for some time now and my fastest pass to date was without the EGR, 24# injectors (gettin ready for boost), and 1.6rr. I do get a code after cruising, and my MPG has not changed.
What value resistor did you jump the wires with? I have MeagSquirt so the SES light will be void,but the light comming on now and again is just annoying (until the MS is installed).
BTW the EGR in my pickup has been slow for about two years now with no decline in performance or mileage (it now has 182k miles on it, EGR went bad at 100k).
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