tcp71
Member
Posts: 88
Reg: 08-31-04
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03-11-05 06:48 AM - Post#646354
Can someone explain the concept behind the EGR system and what happens if I disconnect it. I understand it circulates exhaust gasses into the intake when the engine is warm. But why? Is it only supposed to work when the engine is at running temp? If i disconnect the vacuum hose to the valve in the exhaust manifold, will any damage occur to the system elswhere? Can i damage the cat converter if i disconnect it? Can i damage anything else if i disconnect it? Will my fuel milage suffer or increase as a result? Thanks for any answers.
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Slurfi
Senior Member
Posts: 415
Loc: Lappland, Sweden, Europe
Reg: 03-22-04
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Re: EGR removal question
03-11-05 10:46 AM - Post#646355
In response to tcp71
Just disconnect and ride on.
Thats my humble opinion.
| 1950 Fleetline, Malibu LTZ, Suburban, Impala, RV |
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Zeitler
Senior Member
Posts: 324
Age: 43
Loc: Sweden (Europe)
Reg: 06-21-03
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Re: EGR removal question
03-11-05 01:59 PM - Post#646356
In response to tcp71
look here: Egr removal
i understand your thoughts , i have some problems with the Egr-valve trucks stalling & surging ...guess i need a new egr-valve/soleinoid but they are pricey i've heard
Suburban K10 -87 6 cyl Turbodiesel /Th700 K30 axles 4:56 , 33"
Blazer K5 -88 350/Th700 
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alaskan155
Senior Member
Posts: 645
Loc: In Oklahoma
Reg: 06-04-04
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Re: EGR removal question
03-11-05 02:05 PM - Post#646357
In response to Slurfi
if you are running cats don't remove it, the temps in the exhuast get a little hoter and can fry it from what i heard. also you will loose a little gas milage(from what i heard.)
i personally don't run one because mine didn't work when i got the truck, so i just bought a block of plate from holly from my local parts store for like 10 including the thing of rtv sealent you need to seal everything uup.
aince mine was broke i can't really tell you the pros or cons, i have got rid of the TVS switch on my 79 though by removing it, so that cleaned up theold vacumn line mess out a little bit.
i just need to find a coolent outlet that dosent have TVS switch in it.
if you have emission testing keep it, if you don't then just unhoojk it and block the vac line going to it, if you like how it runs just get a block of plate and put the egr in a box incase you need it in the future.
| 1979 Chevy C10 chyenne big 10
2wd, 12-bolt rear, th375 ,350 Sbc
original 350 Sbc from 79 still going with 160,000+
miles on it with no rebuild.
being restored slowly as i have the funds
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N8sToolz
Very Senior Member
Posts: 2324
Age: 38
Loc: N 42° 53.290' W71° 34.1...
Reg: 10-23-03
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Re: EGR removal question
03-13-05 09:40 AM - Post#646358
In response to alaskan155
if you pull it you will need to adjust the timing a little bit as it will begin to ping because of the mixture change. drive it if it pings then retard teh timing a couple degrees.
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Boog
Super Senior Member
Posts: 4030
Loc: Central Arkansas
Reg: 04-28-02
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Re: EGR removal question
03-20-05 05:04 AM - Post#646359
In response to tcp71
71. Are all the emissions controls in working order now? What size engine are we talking about? In what year truck?
Without going into a long description of how and why the egr works and why it's needed I'll say that if you have a 305 engine you probably need that egr valve on there and working as the 305s are very prone to detonation, pinging, moreso than the 350s. The knock sensor detects this pinging and retards the timing to prevent engine damage. The engine makes better mileage and power with advanced timing.
Disable the egr function and you might not notice any difference around town, more likely out on the highway.
Boog
69 Chevy step
91 Chevy Sportside
06 GMC ccsb Z71
09 Yukon slt 4 wd
All GM...'nuff said!
JR Nation |
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1983G20Van
Super Senior Member
Posts: 3994
Loc: Hurst, Texas, USA
Reg: 11-13-02
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Re: EGR removal question
03-20-05 05:33 PM - Post#646360
In response to Boog
Don't do it!!! Not only will you fail the smog test in alot of locations in the US you will actually hurt your fuel economy. The egr valve is opened by a ported vacuum signal and results in exhaust gases entering into the engine to lower combustion chamber temperatures. The vacuum advance on EGR equiped engines actually advances the timing 6-10* more when the engine is at part throttle to compensate for the EGR. If the EGR valve is removed the engine will ping. The main purpose of the EGR is to lower the temps to levels that will not produce excess NOx. NOx is one of the primary causes of smog. I hear you asking about HP gains. You simply will not see any horsepower gain because the valve should be closed at wide open throttle if it is working right, anyway. Another side effect that was found by using EGR was that it improved fuel economy. By recirculating EGR you more or less help throttle the engine. Since it is lowering the vacuum in the intake, the cylinders see less pumping loss. That means your fuel economy is going to be better. Question is why remove it?
| 1983 G20 Van, 350 TPI, Ported 906 Vortecs, Edelbrock 3817 Base, ASM oversize runners. Reed Custom Roller cam, 700r4, 12 bolt with 3.08 gears, Doug Thorley Tri-Y headers, true duals |
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tcp71
Member
Posts: 88
Reg: 08-31-04
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Re: EGR removal question
03-20-05 06:45 PM - Post#646361
In response to 1983G20Van
The vehicle is an 82 suburban 350 700r4 with 70k miles that is bone stock. There seems to be so much vacuum hose plumbing under the hood and so many devices, i guess i'm just looking to clean up the engine bay to a point where i know what each part is and how it works. It runs very well except of an off idle flat spot(quite minor). It has a cat converter but there is no emmision testing here in Alberta, Canada and i can pretty much do what i want. I just want to have this vehicle continue with its reliability. The only work that has been done is the transmission was fixed after the shell(???basket maybe??) broke. This was in 1997 and has been ok for the last 20k miles on it since then. I occasionally smell gasoline inside the vehicle on cold mornings when it is idling at an intersection. I think it might be the evaporative charcoal canister but i hear you just have to replace that completely. Easy (easily removed, mainly) mods that help drivability, fuel economy or longevity are appreciated.
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1983G20Van
Super Senior Member
Posts: 3994
Loc: Hurst, Texas, USA
Reg: 11-13-02
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Re: EGR removal question
03-21-05 05:30 AM - Post#646362
In response to tcp71
Sun Shell in the 700r4? Early 700s are bad about that shattering in it. The one in my 1983 G20 did when I put my 350 in it. Broke the engine in and then the first time I romped on it BOOM. I now have an aftermarket beast in there and so far so good.
| 1983 G20 Van, 350 TPI, Ported 906 Vortecs, Edelbrock 3817 Base, ASM oversize runners. Reed Custom Roller cam, 700r4, 12 bolt with 3.08 gears, Doug Thorley Tri-Y headers, true duals |
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tcp71
Member
Posts: 88
Reg: 08-31-04
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Re: EGR removal question
03-21-05 08:11 AM - Post#646363
In response to 1983G20Van
That's it, the Sun shell. The dealer replaced it in 1997 so i have to assume they used one from a newer 700r4(hopefully strengthened a bit) and it won't happen again. I baby the truck anyway because if it has a lot of problems, my wife will insist we trade it for a minivan...
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