Correct D15Z1 leanburn info

[slownugly]

Civic VX PCV valve, or lack there of. - Gas Savers - Fuel Efficiency Forum

[VxonFumes]

Hey, thanks for the links. I read through them. Not sure what to say, except that a couple posters there are directly contradicting what Honda corporate is saying, and others are just confused listening to people who don't really know. Honda made the car so my money's with them. Don't mean to be rude, but one whole thread is based on bad info. One poster even said putting a PCV valve on his VX (when Honda calls for one) made his car run worse at low rpm. That makes no sense whatsoever, unless he accidentally didn't seal it up tight & had a leak when finished. Or something else was going on. If there was no PCV valve, every time the crank pulsed vacuum due to piston movement it would be fighting against the intake vacuum. *That* would make it run worse.

It's ironic because the guy who started one thread even attached the picture I was trying to upload but he never included the corresponding parts list that would have shown it as an actual PCV valve!

This should help...part #2 on the illustration is what actually looks like a *normal* PCV valve, but isn't, it's just an empty joint. That threw me off at first too when I took it all apart, and reading through the second thread you posted others have as well. I'm thinking that little detail is the source of a lot of confusion for people. The elbow is the PCV valve, not the joint, and that's according to Honda corporate, not me.

[slownugly]

I have 2 running and driving z1s. Both had pcv valve parts in the elbows. I gutted both and I did not notice a change in the performance or idling characteristics. If they have any sort of pcv or check valve it would be the number 2 part by the breather. That contradicts your statement saying the number 2 is open. I investigated several other threads and the confusion spreads from there. I'm goin to look at both my runnin z1s and both that are sitting in my shop. If thr lower one does have a valve in it, ill gut it and run straight vaccum, and if it runs like total poo poo then I'll agree with you and say that the system was intended for a Pcv valve. It's just nobody's really sure where they are always placed.

Dont always trust dealer diagrams, I just got effed over at work by a Subaru parts diagram faxed to me. The diagram contradicted the part I received and the real part i needed was discontinued by Subaru. The parts guy at the Subaru dealer had to call Subaru direct to find out.

You aren't being rude at all. If i am wrong about it I would rather find out and admit it than keep a closed mind. I was just going by those other posts in the past and didn't really look for contradictions.

[VxonFumes]

Hey, thanks for the open mind! I was afraid I would tick someone off. But technically I'm only passing on what Honda corporate is saying, and so far I've never been burned by Majestic Honda when I go by their parts diagrams, and I get a lot of parts from them. Not to say mistakes don't happen...but I trust them more than forum discussions.

Go to Majestic Honda and take a peek. The way they describe it is exactly the way my own VX was set up, incidentally. Illustration #2 on the diagram is described by Honda as a joint, coming right out of the breather chamber, and that's exactly what it was on my VX too: an empty joint...but from the outside it looks just like a PCV valve so it confused me initially when I could look right through it.

(Under the VX & CX models they don't show it as available, but under all the other models it shows as available and it's called a joint--here's a perfect example of what you're talking about: sometimes things get funny on OEM diagrams even. But all the civics of this generation had the same system according to the fiche diagrams from Honda so in this case it just took a bit more digging.)

And #6 shows on all civic pages from this generation & year as a PCV elbow and they all have an identical part #. And that's what mine was too: I don't see any contradiction here. And even if Honda does cancel production of a part later on, that's irrelevant to this discussion: it was still designed to use that part. So whether people believe me or not is a moot point. I'm nobody. It's the manufacturer they do or don't believe. And I've seen parts guys give bad intel on their own products too, which only confuses things, which is why I try to go straight to the source the parts guys go to when possible. I just wanted to help by shedding OEM light on the subject.

I'm sure you could gut them and it won't *destroy* your performance. You might not even notice the difference by the seat of your pants. But it won't help either, and you will get vacuum interference, even if minor. They were designed to have a PCV valve, like every other engine these days and that only makes sense. Cheers!

[VxonFumes]

by the way, slownugly, how many VX's do you have? Consider sharing the wealth one day?

[slownugly]

Im greedy!!!! Haha. I have the stock vx and a vx swapped sedan. I've had 2 other vxs that I stripped of all the vx specific parts. I have a ton of parts for them.

I really can't believe I'm putting this much effort into a pcv valve system. Kind of ironic out of all the vx specific systems this is the one that gives the most problems.

Anyhow I looked at my 4 z1 engines and 2 d15b7 engines. Low and behold one of my Z1s had the elusive empty valve up top. That in itself totally disproves the majestic diagram. It cannot be looked at as a general 5th gen civic diagram. Who knows how many times it has been revised. In the picture below you will see I have 4 items. The elbow and the blue valve are from the same engine. The brown one is from another z1 and finally we have the b7 on the end.


Both b7s have the empty valve at the bottom and the real pcv at the top. In this case it does follow the majestic diagram. HOWEVER ALL 4 z1 breather valves are NOT empty they all have guts. This also contradicts the majestic diagram. They all have the same p07 part number as tom0 said. Here are some more pics.






In conclusion, if someone were investigating their pcv system to find out where it is look at the breather FIRST!! If the connector looks anything like the blue or brown ones then you are ok to gut the upper one.(if someone has installed a valve, if it's the original open connector leave it alone) If it looks more like my b7 one then make sure the upper elbow has the guts in it. All systems have a pcv valve.

In escense both of us are right and both are wrong. My initial statement about there being no valve on a z1 is wrong and I stand corrected by my findings. And if nobody believes it hey no skin off my back. In the end the worst thing that could happen is someone runs 2 valves and how much will that really affect economy? Probably zilch.

Ok I'm done blabbing.

Edit: oh another thing to note. Both the empty valves on the b7s and the empty elbow at the top of the vx were void of part numbers.

[VxonFumes]

thanks for the long reply...looks like I made you work for it! You're being fastidious...but I appreciate that!

Just for the fun of it...I'm going to play advocate here.

You said: "Anyhow I looked at my 4 z1 engines and 2 d15b7 engines. Low and behold one of my Z1s had the elusive empty valve up top. That in itself totally disproves the majestic diagram."

Does it? Be careful with your inferences. Between your 6 civics (all 5th gen I presume), 4 of which were VX's, and my VX, there was one that was not according to OEM spec up top. That does not "totally disprove" the OEM diagram. Rather, it suggests with a much higher degree of probability that elbow was modified by someone. Corroborating that is the note you made at the bottom pointing out that empty elbow had no OEM part number. It was probably just some Napa part put there by someone who didn't know any better, is my guess. And that's common experience with 20 old civics: most are almost modified into oblivion by kids and shade-tree mechanics that cut corners or don't know all they should. Very hard to find *bone stock* unmodified and unmolested VX's!

The same logic holds for the bottom joint...if it does differ from OEM spec that does not necessarily invalidate OEM diagraming. With that thinking anyone could modify any part on a vehicle and say "see, that proves Honda's diagrams are invalid." That would only be the case if you could say with 100% certainty that none of those joints/elbows were changed on your cars from the day they left the factory 20 years ago and are 100% bone stock. I'm guessing that's an impossibility for you!

Agreed with you on this tough: as long as it's got a PCV valve *somewhere* in the line, I'd be happy with that for my own car. I appreciate all the time you put into this.

[slownugly]

Haha so how do you know your straight valve wasn't modified?? Because they don't have part numbers either!!!

Even though all of my z1s have the original part numbered lower part you are suggesting they came from the factory with 2 pcv valves?

What year is your vx? Can you take a pic of your bottom fitting? My 92 and 93 engines had the blue valve. The other 2 are out of 94s and they have brown valves. Maybe if yours is a 95 they flopped them that year.

TomO nailed it in the first paragraph of his thread.

"Make sure to check the vacuum/PCV hose going into the black box on the back side of the engine block to see if your PCV valve is located there. If you are able to to remove it, clean it, and still have it work, then you may use it again or if you can obtain a replacement OEM style to use. If you can only get the 90* "normal style" then use this guide to "gut" your OEM straight PCV valve and install the 90* unit up on the intake manifold runners for ease of maintenance/cleaning/replacement in the future."

I wish I would have read it closer before.

[slownugly]

The diagram isn't going to convince me so there's no point even bringing it up anymore. Majestic does have vx specific diagrams (intake manifold, exhaust manifold, rocker arm assembly) but the breather diagram has an intake manifold from another model. Note the FITV valve under the throttle body. Just that alone scares me away from believing it.

[VxonFumes]

Hey slownugly...sorry, but I don't feel like crawling under there to take the bottom joint out of the breather for a photo. I'm not that ambitous.

You're right, the breather diagram for the VX is off another model. The PCV system is the same for all the 5th gen civics so they consolidated this diagram. I'm not worried about that personally, even though the CX and VX lack a fast idle valve. (I noted that earlier in this thread actually.)

Sounds like you don't trust Honda diagrams very much. I can sort of see where you are coming from, but I still trust them...they were the manufacturer.