EGR question.

[s10cky]

Hi,

I just recently started having the common s13 idle problem. the revs drop when coming to a light with my foot on the clutch then jump back up. I did a search and found out about a few emission systems that could have too do with the problem. I then decided to remove one system. Its the system on the right side of the motor that routes exaust has into the intake. after removing it and blocking of the vacume hoses it still does the same thing.

my questions are.

1. if I remove the egr setup will my car run differently, will it throw any codes?

2. Can I use the existing vacume hoses that I caped of to run a boost gauge or for a bov?

3. Has anyone used seafoam to flush the air idle control setup and did it help?

,matt

[Touchdown038]

1. It should run about the same. You might have to retard the timing a bit, since the combustion temperature will be higher. You obviously won't be able to pass smog if you do this, don't know if SC has smog laws... it will probably throw a code but I'm not sure about that.

2. Yes.

3. Yes. Seafoam works wonders, especially in high-mileage motors where carbon buildup is high. You might even wanna take off the IACV valve (on the back of the intake collector) and give it a spray with carb cleaner.

[Q45tech]

Highway cruise MPG will drop by 1-2 MPG as the burned inert gases displace some incoming air thus less fuel is needed to turn same rpm under same load.

[s10cky]

wow, there are alot of effects of removing it. the reason I removed the aiv, and am going to remove the egr is because im going turbo ont the stock blcok.

[s10cky]

Highway cruise MPG will drop by 1-2 MPG as the burned inert gases displace some incoming air thus less fuel is needed to turn same rpm under same load.

would a turbo make up for this?

[s10cky]

4. will removing the charcoal canister and pluging the vacume lines effect the way the egr works now.

[navysnail]

turbo uses even more fuel as it pushes more air into the combustion chambers. To maintain the stochiometric air-fuel ratio, it must put in more gas. this is why turbo cars often have larger injectors with a higher flow capacity.

the charcoal canister just burns fumes from the tank so they are not vented instead. there is really no reason to remove it unless you need the extra space in the engine bay.

you may also want to check your idle air control valve or your mass airflow sensor (MAF).

[Q45tech]

At cruise the throttle plate restricts the air flow to hold equilibrium [maintain a steady speed]. Creating a lower than atmospheric pressure in the plenum 18-22 " HG [8-10psi vs 14.7 psi]..............EGR sending in 10-15% already burned exhaust means the cylinder is filled with Oxygen weaker air [instead of 21% O2 the cylinder air contains 17-18% O2.

Also the exhaust has a tiny pressure [after passing thru the EGR system] so this 10-15% exhaust air is weakly force feed into plenum after the almost closed throttle plate..........Thus the engine doesn't have to work as hard to fill the cylinder and has less drag to create the same power at cruise.

EGR shuts off at idle and acceleration only active after warmed up coolant and cruise steady rpms........the amount is variable controlled by ecu and plenum so called vacuum [actually just lower than atmospheric pressure].

You might find some of this interesting:http://www.eng-tips.com/viewth...age=1

http://yarchive.net/car/air_induction.html

[s10cky]

wow, thanks for the greats info guys. I learned alot.