marcin

With the ITB's pull 17inches at idle when i dont have the pcv sys hookeked up, but when i do, im pulling like 10. Im thinking it may be my pcv valve but then again, at idle it shold be open and pulling form the crank case right?
The set up goes form the black box to a catch can with pcv valve on top and then to the vac canister. I checked the catch can and before and after give same results, gain in vac.
Could it be blow by?
Can anyone shed light on the pcv system and possible issues?


thank you for any suggestions, Im going to start by replacing the pcv and go from there. dont want to pull everything off but may have to

m.

marcin

could having a filter on the valve cover be causing the loss in vac? Since then its not a sealed system? However in that case, how does the stocker work since its in the intake tube tract? Is vac created by the air passing over the hole down the intake tube?

any help appreciated.
thanks
m.

2point6

bump

marcin

thanks man.
here is what rocket said on another forum. makes mucho sense and much help

"The PVC valve is shut under hi and low vacuum.

Most PVC valves are basically a tubes with a ball bearing inside. Under high vacuum the ball is pull up and seals the on the top and under very low vacuum the ball bearing falls to the bottom and seals the bottom. Thats why most PVC valves have to be installed vertically.

I am very glad you posted this as this can be a "mysterious" source of low vaccum.

Clean the PVC with some solvent or by another one."


m.

nitrofish420

From my understanding, the PCV is never "closed" unless a backfire occurs, in which the manifold pressure forces the PCV valve closed.

marcin

im going to get a new valve, but a thing to think about. the ball is in the vertical portion of the valve... meaning when being sucked on. it would pull up and close off the opening.

m.

Rocket

You can suck on the PVC valve to see if it sealing. (clean it first though).

2point6

So rocket, are you suggesting the pvc valve is just blocked or bad in this case?

I also noticed this drop in vacuum when I went to ITBs. Is there a betterway to keep the pcv circuit working for emmision purposes?


Modified by 2point6 at 8:41 PM 11/20/2005

marcin

it may be one of a few things but i bought a replacement FRAM piece and im experiancing the same thing.

I tried blowing through the valve and it seals down but not up. stock and FRAM gave same results.
perhaps I just bought a bad valve. I will get a oem one because I really want to eliminate this part of the equasion. I did notice that it builds vac when i seal the breather on the valve cover.
It is also possible that the lesser vacum from the itbs is not sufficent to seal the valve.

will research helms and report back.

curious 2point6 do you have your pcv hooked up to your vac can?
m.


Modified by dvious hatchie at 9:07 PM 11/20/2005

2point6

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dvious hatchie &raquo;</TD></TR><TR><TD CLASS="quote">

curious 2point6 do you have your pcv hooked up to your vac can?
m.
</TD></TR></TABLE>

Currently no... I am working on an electric air pump for the crank case to replace the PCV, but it is not working yet.


Modified by 2point6 at 8:40 PM 11/20/2005

marcin

checked helms
92-95 manual 11-140

"The positive crankcase ventilation system is designed to prevent blow-by gass from escaping to the atmosphere. The PCV valve contains a spring-loaded plunger. When the engine starts, the plunger in the pcv valve is lifted in proportion to intake manifold vacuum and the blow by gas is drawn directly into the intake manifold."

diagram shows that the air goes in through the valve cover through the crank case and through the PCV vlave into the intake mani(vac source)

i will look at it more theraly later tonight. Any insight?

thank you
m.

2point6

Well, that makes sense... the reason the vacuum is dropping. The PCV valve works one way and not to contradict Rocket but his explanation at this point, to me sounds confusing.

I am sure the best way to cure the blow-by issue is to use an air pump on the block (or dry sump) to make a vacuum.

marcin

i agree. My thinking is that with the addition of itbs to a system designed for a single pleneum set up you loose vac quantity and quality. Because we are pulling from 4 throttle bodies and constantly loosing in one or the other, we are pulling less vac in inches and also the vac is not as stable as a single pleneum. I feel that with the single pleneum although its pulling through the vc and the crank case, its still able to maintain enough vac to keep the inches up.


m.

2k.civic.si

the pcv valve is so cheap just replace it

sohcnotec

Well keep in mind that the PCV system is actually like a "controlled vacuum leak"
You could maybe try another PCV valve that may flow less. From what car?? That I don't know.
Some cars don't have a PCV either they use a small orfice rather. Which does the same job.
Maybe you could somehow modify your stock piece to flow a lil less?

marcin

perhaps a valve to balance the leakage

m.

2point6

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 2k.civic.si &raquo;</TD></TR><TR><TD CLASS="quote">the pcv valve is so cheap just replace it </TD></TR></TABLE>

I love input from people who don't speak from experience. "Just replace it"... sounds so easy, but if you read it was already done. I also tried to replace mine as a fix, but from what I have learned since is that most people with ITBs vent this to the atmosphere anyway.

Start with what a PCV valve is... it allows gasses (burt or unburnt) to re-enter the combustion process. This was done for emmision purposes and is a process different than just venting the crank case.

ITBs are not emmisions compliant, so why worry about recirculating spent air?

The use of an air pump or dry sump to vent the crank case is not to be confused with the PCV circuit.

marcin

on a side note, i like trees. so i got 2 out of 3 vechicles LEV(low emisions vechicles) lol.

i plan on tryng a shop vac on the dyno one of these days too.

m.

2k.civic.si

"I love input from people who don't speak from experience. "Just replace it"... sounds so easy, but if you read it was already done. "

i love how ht is full of ******...wonder how it got the name hater tech

2point6

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by marcin &raquo;</TD></TR><TR><TD CLASS="quote">

on a side note, i like trees. so i got 2 out of 3 vechicles LEV(low emisions vechicles) lol.

i plan on tryng a shop vac on the dyno one of these days too.

m.</TD></TR></TABLE>

lol... 2 outa 3 ain't bad.

Let me know if the shop vac works.

2point6

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 2k.civic.si &raquo;</TD></TR><TR><TD CLASS="quote">i love how ht is full of ******...</TD></TR></TABLE>

You say that like you know me.

Don't get your panties tied up... this is just the internet.