has anyone removed the egr system on a renix model?

[offroadman73]

just a thought. do yall think it will work? found nothing on a search. i would like to remove the egr tube, valve and canister! please help! ===BRIAN

 

[xjtrailrider]

just a thought. do yall think it will work? found nothing on a search. i would like to remove the egr tube, valve and canister! please help! ===BRIAN

Well you most likely will not find anything about removing the EGR since it is covered under federal emissions laws, I'm no EPA nazi but I wouldn't do away with it.

However for testing purposes you
could disconnect it, plug the line or make a block-off plate to go between the EGR and intake, you would need 2 gaskets for this test, one on both sides of the plate.

Most EGR issues are from it staying open giving high idle and stumbles.

 

[badron]

Do you have a ajustable timing and a quite muffler. If so you may need to back off the timing if you get a ping after disabling the EGR system. The factory setting is generally safe but many engines have had there timing bumped up. In an effort to improve MPG or bottom end torque.
With a loud muffler it's much harder to detect the ping and a lot easer to get into trouble. Besides being down on power.
With a loud muffler you can still tell by watching your plugs if the distortion isn't to bad. But this gets to be a real drag on a DD.
If the time is way off you can QUICKLY end up with a chunk of plug porcelain in the cylinder. Witch can eat up a wall/piston in no time.
I myself have never seen a hole in the piston of any gas buring non forced draft induction engine do to timing.

 

[cal]

I had a bad EGR valve a while back, so I blocked mine off temporarily. Economy tanked and it ran poorly, put a new EGR valve in and it all came back.

I wouldn't do it based on that, but also lets not forget its illegal, and we generally don't discuss illegal mod's or activities that are harsh on the environment. =)

 

[5-90]

I had a bad EGR valve a while back, so I blocked mine off temporarily. Economy tanked and it ran poorly, put a new EGR valve in and it all came back.

I wouldn't do it based on that, but also lets not forget its illegal, and we generally don't discuss illegal mod's or activities that are harsh on the environment. =)

'S funny - I had exactly the opposite results when the EGR when TU in my 1987. Power got a bit better (per Butt Dyno[tm],) economy dropped when I fixed the thing (I lost 4-5mpg,) and emissions actually got worse per CARB test before/after!

I know the theory of the EGR, but our compression is low enough that it doesn't really apply here.

Emissions laws are a case of something that really needs to be overhauled. I'm all for protecting the environment (to enjoy it, mind,) and I'm not going to advocate actively doing anything in violation of EPA/CalEPA regs (asinine tho they may be,) but I've been agitating for a review of at least CalEPA regs for several years. Laws are, in general, written for the "average person" - and these days, the "average person" is generally a schmuck. Sorry, but that's all there is to it.

But, the only way we can get these things changed to become useful is if we let everyone know who actually writes these asinine rules that they're not helping - and, in some cases, they're actually doing more harm than good!

 

[offroadman73]

thanks guys! no emission laws here! the jeep is a trailer queen that i will use only a few times a year. if it was a dd i would not even consider it. honestly. i would rather run it on propane, but it is too expensive.-----BRIAN

 

[Built2Flex]

I took mine off, everything you described. Runs great and never looked back. Sweet home Alabama, no emission laws.

 

[Johnnie Walker]

Any of you who removed the system.. did you use a plate to block off from engine? If so, what kind and did you make it or buy it? My hose from egr to block is toast. Just curious.

 

[Stallacrew]

I took mine off and tried the plate idea, but I used a piece of rubber gasket making material to seal it. work very ineffectively amd I ended up just putting the valve back on without any hoses to it. It slays closed that way and I plugged the hole to either side of the pipe by welding it.

 

[Johnnie Walker]

I took mine off and tried the plate idea, but I used a piece of rubber gasket making material to seal it. work very ineffectively amd I ended up just putting the valve back on without any hoses to it. It slays closed that way and I plugged the hole to either side of the pipe by welding it.

SO without the tube, it is closed?

 

[Sherman_thetank]

I made a blocker plate out of a piece of scrap. Beware millage goes down dramatically, but more power is nice

 

[Johnnie Walker]

Like I said, my tube from valve to block is tore up anyways.

 

[88 Wagonman]

I have a 98 longblock in my 88, and I plated off the EGR valve because supposedly the HO camshaft has more valve overlap between exhaust and intake essentially doing the same thing. I didn't notice a change in mileage or horsepower, but I did end up with better emissions test results, even lower hydrocarbon levels which the EGR valve is designed to lower by lowering combustion temps.

 

[5-90]

I have a 98 longblock in my 88, and I plated off the EGR valve because supposedly the HO camshaft has more valve overlap between exhaust and intake essentially doing the same thing. I didn't notice a change in mileage or horsepower, but I did end up with better emissions test results, even lower hydrocarbon levels which the EGR valve is designed to lower by lowering combustion temps.

Half marks. The intent of the EGR valve is to lower NOx emissions by lowering combustion chamber temps.

It's a tradeoff - having the EGR makes the catalys ever more necessary by increasing HC and CO emissions (lower chamber temps inhibit combustion - HC and CO emissions are the result of incompleat combustion.) However, with low-DCR engines (like ours...) the EGR is of specious utility at best. If an engine has plenty of "quench" (which results in eversion of the fuel/air charge) and a relatively low DCR, the EGR is going to increase HC and CO with minimal decrease in NOx (since there isn't much in the way of NOx emissions from the off.)

When I got my 87, I had to get it smogged. The EGR had failed - as noted by the tech playing around with the thing. HC and CO emissions were right around zero, with NOx running right around zero at well (standstill test, idle/2500RPM.)

However, the EGR was manually tested and found to have failed. So, I had to go replace the thing and get retested. No change in NOx, but HC and CO emissions were just barely passing.

Tell me again how necessary this thing is - I just love to hear spurious logic! Minimal change to fuel economy, and I did notice a power drop (somewhat slower acceleration, harder time "pulling," harder time getting up to pass) after replacing the thing - which does make some sense. The EGR is exactly what it says on the tin - it "recirculates" exhaust gas into the intake stream. This is like burning wet wood - you can't get the fire as hot as you should be able to.

Meanwhile, we now have three-way catalyst beds - they work on HC (oxidising,) CO (oxidising) and NOx (reducing) - with the reduction of NOx emissions providing most of the oxygen needed to oxidise the HC and CO emissions (the rest is generally provided by an overpriced and failure-prone "smog pump" that pushes fresh air into the exhaust stream and into a three-way catalyst bed.)

As far as the EGR itself, I'd like to see the thing replaced with a fogger system fed with MeOH and water (methanol is cheaper because F troop doesn't tax it...) which will not only reduce NOx emissions, but won't crap up the intake with carbon, and will help to keep the combustion chamber clean (which will help to keep "ping" and "knock" down as well - win-freakin'-win, baby!) Foggers have been around since WWII, when the Allies were trying to gain air superiority through increasing aircraft engine performance and increasing the operational ceiling of piston-engine driven aircraft. It's simple, it's proven, and failures are damned near zero (you just have to keep the supply tank filled up, and that can be sized to coincide with fuel fills without too much trouble. I seem to want to recall that you'd go through about one gallon of "fog water" for every ten gallons of fuel, so the tank size need not be great.)

 

[88 Wagonman]

Half marks. The intent of the EGR valve is to lower NOx emissions by lowering combustion chamber temps.

I get them mixed up sometimes:dunce:. Thanks for setting me straight.