Why isn't my EGR throwing a code, civic vx help!

[turbothrush]

Originally Posted by steffen707

Yeah just try crusing around at 3500-4000rpm in any gear. I noticed the vacuum on the egr hose occured more often when you accelerated a bit like from 65-70mph in 4th gear and then let off the throttle to enter into lean burn. It would then show up.

Its funny though because in 5th gear doing the same thing it wouldn't do it. Not even once with my car. And I drove around for 30 miles on the highway testing it.

Yep , I found the same thing. Egr gets activated only above 3000 rpm or so and then only for a couple of seconds before you select the next gear, In fact the way I normally drive the car I would hardly ever activate the egr.

I certainly was not expecting this. I always thought a good working erg was one thing needed for good highway fuel mileage in the vx. Seems to be really just for emissions I guess.

One thing I did notice is if while in leanburn cruise you apply some vacuum directly to the egr ,the instant mpg goes up 2 mpg or so and then when you release the vacuum it goes down the same amount . I only tried this a couple of times for a few seconds so it requires further testing on a nice flat road with zero wind . I am thinking somebody must have already tried this idea ...Gotta love the MPGuino for this stuff

[steffen707]

Originally Posted by turbothrush

Yep , I found the same thing. Egr gets activated only above 3000 rpm or so and then only for a couple of seconds before you select the next gear, In fact the way I normally drive the car I would hardly ever activate the egr.

I certainly was not expecting this. I always thought a good working erg was one thing needed for good highway fuel mileage in the vx. Seems to be really just for emissions I guess.

One thing I did notice is if while in leanburn cruise you apply some vacuum directly to the egr ,the instant mpg goes up 2 mpg or so and then when you release the vacuum it goes down the same amount . I only tried this a couple of times for a few seconds so it requires further testing on a nice flat road with zero wind . I am thinking somebody must have already tried this idea ...Gotta love the MPGuino for this stuff

I didn't try that, I only hooked up the vacuum pump/gauge to the egr valve when it was connected to the egr solenoid with a "tee" fitting. You probably noticed you can't apply vaccum when its like this because the egr solenoid isn't activated and thus i think is just venting to atmosphere. You can only apply vacuum to it in this manor when the ecu is already activating it.

However if you hook the pump directly to the egr valve then you can do it anytime.

Is that what you were doing?

I can't wait to test this, and hear your results, wonder if this could be a nice way of warming up the intake and engine quicker when its stone cold.

[turbothrush]

Yes that's what I did . The valve does not operate on my commute anyhow so just for fun I thought I would make it work from inside the car and see what the instant mpg does over a nice flat road . I can make it activate or deactivate at will.
Did you notice an instant mpg change on your mpguino when you cycle your alternator charge wire ? Thanks

[steffen707]

Originally Posted by turbothrush

Yes that's what I did . The valve does not operate on my commute anyhow so just for fun I thought I would make it work from inside the car and see what the instant mpg does over a nice flat road . I can make it activate or deactivate at will.
Did you notice an instant mpg change on your mpguino when you cycle your alternator charge wire ? Thanks

Its hard to say. I did a few tests, one at .5 miles, one at 2.5 miles long.

The tests pointed to a 3-4% over highway speeds, and up to like 13% gain when there are a lot of electrical loads on the car at 40mph.

While I did notice the 13% gain on mpguino right away, with the other tests the amount is so minute it couldn't be noticed because my foot might not have moved on the throttle to change the 1-2mpg change that occured; however, over the long 2.5mile test what I think I percieved was that when driving with the alternator on and maintaining a speed with my foot still on the throttle if i switched the alternator off, the car started to accelerate. The mpg didn't change, nor did my throttle angle, however with less load on the engine, it seemed to accelerate a little.

Then if I would back off the throttle to try and maintain the pre alternator shut off speed, the mpg would go up.

Remember my alternator shut off mod doesn't totally shut off the alternator. it only puts it at low charge mode. I'm going to do some more tests tomorrow when I totally unplug the alternator as well.

[steffen707]

Originally Posted by turbothrush

Yes that's what I did . The valve does not operate on my commute anyhow so just for fun I thought I would make it work from inside the car and see what the instant mpg does over a nice flat road . I can make it activate or deactivate at will.
Did you notice an instant mpg change on your mpguino when you cycle your alternator charge wire ? Thanks

I'm also going to try activating the egr like you did on an accross town trip that i've done a few times and see if i can get it to go into the 70mpg range. I've come close but never hit 70mpg on this 4 mile in town drive, but if playing with the egr i'm able to, I think I might have found a fun little way to get more out of the car.

Do you think running for extended periods of time with the EGR open can cause harm to the engine?

[turbothrush]

Originally Posted by steffen707

I'm also going to try activating the egr like you did on an accross town trip that i've done a few times and see if i can get it to go into the 70mpg range. I've come close but never hit 70mpg on this 4 mile in town drive, but if playing with the egr i'm able to, I think I might have found a fun little way to get more out of the car.

Do you think running for extended periods of time with the EGR open can cause harm to the engine?

I can't imagine that it would but I am no expert. I have read that many cars now use egr to improve fuel economy (reduced pumping losses so they say) . I thought the vx did as well, but its looking to me that it is for emissions. I wonder if the the hx and Insight is the same. Maybe not since they are newer but just he same I would love to know.

Keep in mind if you play with this, the egr on the D15Z1 only takes 1" of vacuum to begin to open and with 5" Hg it is full open (on my car).I have a big 3 1/2" guage so I can see this easily. If you go crazy with the pump and put 15 or 20 " you may actually cause a leak.

Seems to me Doax had a thread on egr

Also noticed and confirmed what Metro had posted a while ago about the vx alternator -- Full charging above 50 mph even with lights off .Highway driving is most of my vx use so I am interested in the alt wire/switch stuff with solar recharge. Thanks

[steffen707]

Originally Posted by turbothrush

Keep in mind if you play with this, the egr on the D15Z1 only takes 1" of vacuum to begin to open and with 5" Hg it is full open (on my car).I have a big 3 1/2" guage so I can see this easily. If you go crazy with the pump and put 15 or 20 " you may actually cause a leak.

I'm not sure it will let me go higher than 5, but maybe it would but i just noticed that it does nothing more if you go higher than 5.

I'm going to screw around with this tomorrow for sure, because if this works and gives way better mileage, I might play with sending a signal to the egr control valve to actuate the egr at will. with a push button.

Now i'm going to have to put 2 buttons on the shifter, one for EGR, one for injector cut off. And then the switch on the dash for alternator.

Sooner or later this car is going to look like a damn airplane.

[steffen707]

Originally Posted by turbothrush

Keep in mind if you play with this, the egr on the D15Z1 only takes 1" of vacuum to begin to open and with 5" Hg it is full open (on my car)

Where did you read this becaue when I read the 92-95 civic vx shop manual on pages 11-134 to 11-139 it said that if you ground the B wire and supply battery positive to the a wire on the black box that within 1 second you should see 8" of vacuum. I'll have to test this again because 6-9 months ago I swear my tests did exactly what the manual said they should, but I did notice that after about 5" on the egr valve itself, nothing much more happens.

Is the CVC valve just there to regulate the vacuum coming from the engine to provide 6"-10" of vacuum to the egr control solenoid valve?

[steffen707]

Here are a few great reads on what we're discussing, and a quote from the autospeed site.
http://ecomodder.com/forum/showthrea...ge-7358-2.html
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"in lean cruise, the Insight’s EGR valve is closed. At idle and under full throttle, the valve is also closed. In fact, in normal driving it is closed far more often than it is open. So when is it open? The valve is open its greatest amount (about 50 per cent duty cycle) at light and moderate throttle, at both low and high revs. It also opens when the car drops out of lean cruise to consume its stored NOx emissions (see Giving the Insight a Good Driver for more on the lean cruise behaviour of this car). Finally, it is open for a short time on throttle lifts. "

[steffen707]

"The flow of EGR is determined not only by the control valve opening but also by the difference between the intake manifold and exhaust manifold pressures. Therefore, if a free-flow exhaust is put on a car, EGR may decrease because of the lowered exhaust backpressure. That’s especially the case in a diesel, where there is no intake manifold vacuum."

From the same autospeed article. I've been meaning to ask this question. I have a huge hole in my muffler. Thus less backpressure. So maybe my EGR will work more then? I was also wondering how putting a new muffler on the car will change my normal NON EGR ACTIVATED mpg. I think it will increase the mpg under most conditions, but it might make less power when driving 65mph, thus making it harder for me to maintain lean burn.

Either way i'm waiting for a $50 off coupon from advanceauto so I can buy a new muffler on 4/11. This thing is getting stupid loud. I'm hoping for 20mpg increase....LOL JUST KIDDING.