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

[turbothrush]

Originally Posted by steffen707

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?

Well I didn't read it anywhere I just connected my vacuum pump to the egr and with my finger touching the egr plunger I could tell the range is from 1-5 " hg on the gauge.

When I applied battery voltage to the box like you said I only got 7" not 8" like the book wants. I'm not too worried about this since while driving I am never in the egr zone anyway.

I think the vacuum actually gets reduced (from engine vacuum) by the small plastic tube thing placed in-line in the hose coming from the engine. I removed it to have a look and it has just has a small hole to provide a restriction

I doubt that you could just open the valve say half way with 2 1/2 of vacuum , go for a drive and expect to see an improvement in mpg . I was thinking more for along the lines of giving a little egr during steady state cruise and maybe pick up a mpg or 2. If I could get that I would be happy. I really want to get 60mpg at a true 60mph flat road/no wind/summer temps. I may have to build a bellypan or do an alt delete to get that.

[steffen707]

I did some tests, all were with limited electrical load, on a 1 mile stretch of road. The car was up to temp, cruising at 40mph. I reset mpguino at the first marker and noted the MPG at the 2nd marker before slowing down.

A-B test route:
without egr: 81.9, 82.4
with egr at 8": 75.23, 73.5

B-A test route:
without egr: 73.2, 74.5
with egr at 8": 64.5, 64.3

I didn't bother doing more testing, or try to limit the " of vacuum to less than 8". I kinda decided that with the results of this first test it didn't make sense to continue. I don't think the EGR can help get better MPG. Though it might reduce pumping losses by having to increae the throttle, it did make many driving conditions harder to maintain lean burn. For me anyway.

[turbothrush]

Originally Posted by steffen707

I did some tests, all were with limited electrical load, on a 1 mile stretch of road. The car was up to temp, cruising at 40mph. I reset mpguino at the first marker and noted the MPG at the 2nd marker before slowing down.

A-B test route:
without egr: 81.9, 82.4
with egr at 8": 75.23, 73.5

B-A test route:
without egr: 73.2, 74.5
with egr at 8": 64.5, 64.3

I didn't bother doing more testing, or try to limit the " of vacuum to less than 8". I kinda decided that with the results of this first test it didn't make sense to continue. I don't think the EGR can help get better MPG. Though it might reduce pumping losses by having to increae the throttle, it did make many driving conditions harder to maintain lean burn. For me anyway.

Thanks for the test. Sure looks bad for sure . Just for fun I'll do the lower percentage egr in the next day or 2 and post here. Really great work on the Alt Delete test in the other thread.

[steffen707]

Originally Posted by turbothrush

Thanks for the test. Sure looks bad for sure . Just for fun I'll do the lower percentage egr in the next day or 2 and post here. Really great work on the Alt Delete test in the other thread.

Thanks turbothrush! I'm glad people appreciate, and i'm glad to help as others have certainly helped me as well.