rough idle

[chevymaher]

I know the therory behind it. But the seat of the pants thing what I lookin at.Before 5-6 foot of rubber. Now spin through first into second.Climbs steep hills in fourth it used to drop to second for.If its performance is reduced I will take it with the better mileage and run with it.I half tracking the vans with EGR PVC and stock timing.Just blocking the EGR made the exhaust tone deeper instant throttle response improvement.I did not have to worry about breaking the tires loose taking off before.Now if I pull into traffic I cant drill it or i will spin and not move forward.Which is a problem when someone behind you coming.Trust me therory and reality are different animals.Ask yourself this if it truely improved performance dont you think stock cars and dragsters would use it.Really thats the name of the game in racing performance.

[smokienutz]

if i get rid of of this egr. will it still pass smog? being in this grand state if california,(sarcasm alert). they don't like hp, fun or custom stuff.

[chevymaher]

You have to have the chip reflashed to get rid of code.Dash light wont come on but it will read code.I used to live out there and yes they sticks in the mud about some stuff.Do what we did.Just take out block plate disconnect battery 5 min.Then test.Go home put it back on.Alot better than what we went through out there.Putting factory exhaust on once a year what a pain.Once you good at it only takes a half hour to put on and take off.Really some one did dyno test on smog motors and a race type engine with decent cam to show how important smog devices were.Well no matter how hard they tried they could not get the smog motor to burn cleaner than the performance motor.So at least in this state they were man enough to admit defeat and got rid of smog testing.

[MountainManJoe]

You're upsetting the balance of a system that has been finely tuned to work in harmony with the other systems. When EGR isn't flowing, your ECM will thinks the engine is 'sick', and will retard ignition timing, killing your performance. You are also increasing combustion temperature, which will increase detonation and engine ping.

I hope your country has a good health care system, because when your kids get respiratory problems from sucking your smog ... oh yeah, you don't.

[chevymaher]

I

[Kidhauler]

Timeless is right on basically everything he said about the function of the egr valve. I worked at the testing centers here for years. These vans are designed to run with the egr in place you can't tune the van to run correctly without it. The only way would be to totally rewrite the computer program. Chevymaher I am sorry to be slagging on you but your advice is wrong and in most areas illegal. Instead of going caveman and ripping off all the pollution control try checking the plugs, leads and the cap and rotor. If the plugs are starting to go it will start missing in gear when you have more load on the engine.

[MountainManJoe]

I never said anything about global warming or ozone holes. I'm talking about air quality, and that brown blanket of air that you see over the city when it's clear and sunny out. Go visit a city with heavy air pollution, and see how much people outside are "enjoying life". Oxygen mask ... yeah that sounds like fun. I don't give a damn about you since you already seem to have one foot in the grave, but some of us are going to be around for while. You can defend your attitude with all the ignorant banter you want, but they're just excuses. Look, I don't buy all that "green" BS that people are ramming down our throats. It's always someone trying to make money. But everything you just said is plain dumb.

[chevymaher]

it

[MountainManJoe]

He deleted what he just posted, but Chevymaher was basically explaining that as long we are doing damage, we might as well go balls-out and do it faster.

[MountainManJoe]

By the way the EGR valve is modulated. It closes off the more the throttle opens. At wide-open-throttle there is no exhaust going into your intake.

[v8famvan]

Chevymaher was basically explaining that as long we are doing damage, we might as well go balls-out and do it faster.

Oh, that's a great line of thinking!

I won't get into the use/purpose/reasons & functionality of the egr valve as it has been done justice in this thread already.

Getting back on track to the topic of this thread ...... rough idle. EGR is one possibility, however, probably not the source as it does not match the symptom/information given.

Original post stated that the air filter & pcv valve was changed, THEN the rough idle started to occur. If this is accurate information, then a vacuum leak is a reasonable explanation as this will affect the fuel mixture most at idle. You should look back at what was touched/changed.
Now, granted that a leaking/improperly sealed egr valve is essentially a vacuum leak, why right after changing the air filter & pcv valve?
However,
IF you put in the wrong rate of flow pcv valve, you could have a rough idle.
If you bumped some brittle vacuum lines, you could have a rough idle.
Start with the basics & K.I.S.S. (no explanation needed for this is there?)
Diagnosis is a process of elimination, start simple.