RJC PCV Valve ?

Eric Stage I said:
Lee, you should be able to blow up through the bottom, but you should not be able to blow down through the top on the 1162 (unless there's something wrong with it).
Eric
Click to expand...
And you should NOT be able to suck up through the top, correct?

For years I've run a leaky stocker along with an old-school ATR check valve and seen high BLM's at cruise, I think the PCV working OK. I installed a Kirban PCV valve on its own and lost my power brake assist - - massive vac leak. If I run the old stocker alone - - same vac leak. ATR valve on its own - - small vac leak but PCV works, no boost down through the top...

This is indeed confusing :(
 
Do yourself a favor and go here:

Check Valves | U.S. Plastic Corp.

Its a good idea to change all your check valves in your system and you can add the one for the PCV. These have a Viton diaphragm and work really well, the price is right. I use one of these with my stocker PCV, works like a charm and will last a hell of a lot longer than the stock checks....

HTH
 
EVIL said:
I do believe the RJC PCV is a direct replacement.

RJC PCV

D
Click to expand...
That's the same valve Kirban sells, advertised the same way. As I said, I installed it alone as it says and it's a HUGE fluttering vacuum leak. Needs the stocker in line with it as TurboDave says.
 
interesting. maybe something is wrong with it. It would be great if the people selling these direct replacements would chime in.

D
 
Gotta say some things in this old post before someone finds it and starts chasing their tails again. 1. How do you figure an inline check valve will help out a potentially leaky pcv? If the check valve is stronger and more reliable, then the pcv valve itself is a screen door on a submarine. If your "inline" check valve is doing all the work, guess what; it's not an inline check valve any more lol, it's the pcv now. There shouldn't be a "conjunction" check valve inline, meaning along with it's own sealing capabilities, they all combine along with the original pcv to add up to the proper amount of sealing/relief required. It doesn't work that way.
And the whole blow thru from the bottom or "shake it and listen" tests are not only inadequate but completely worthless. I used to replace pcv's on customer's cars like it was going out of style. About half passed these tests, but failed MY test horribly, which was to pressurize the top side with a pressure gauge to see, and also to apply vacuum to see what it did. Some valves failed the blow in the top test, but sealed when I applied real pressure. From the massively wide variance in qa/qc I've found on pcv valves I've switched to the more robust all brass valve you see these vendors selling. I will never use a standard issue pcv valve from autozone again. The cracking pressure on this valve is a little higher but it holds more boost than any pcv valve I've tested. If you're running a bone stock setup you should be able to get away with a stocker (maybe) but the second you reach for that wastegate rod I think you're basing your success on how much marijuana that pcv valve assembler smoked that day.

And for all those guys who invariably state "The blow thru test on the autozone pcv valves have always worked for me" are the exception not the rule I think. If you guys want pressures I can test them again tonight to see.
 
The PCV restricts the airflow under vacuum, a simple check valve does not. The check valves are being installed because the PCV is not satisfactorily closing under boost. This wasn't necessarily a bad thing in a stock config where vacuum was generated from the pre-turbo hose into the passenger cover. Since almost everyone removes the pre-turbo hose, the sealing quality, or lackthereof, of the PCV becomes acute, hence the check valve.
 
ravege said:
The PCV restricts the airflow under vacuum, a simple check valve does not. The check valves are being installed because the PCV is not satisfactorily closing under boost. This wasn't necessarily a bad thing in a stock config where vacuum was generated from the pre-turbo hose into the passenger cover. Since almost everyone removes the pre-turbo hose, the sealing quality, or lackthereof, of the PCV becomes acute, hence the check valve.
Click to expand...
So the suggested fix is to replace the PCV with a check valve, and do away with the PCV entirely?
 
I'm not sure if this have any effect on this subject but I had an RJC PCV installed and started noticing high blm's at around 138 to 140.

After doing a bunch of trouble shooting that didn't correct the problem i switched back to the factory PCV and BLM's are back to 127 to 132.

D
 
There is no one fix, one camp will say plug the pcv and run nothing but breathers. Another camp will say run a dedicated vac pump. Etc, etc, etc. What I got from Eric is that the stock ECMs are calibrated for a certain assumed vacuum loss. With ported this and that, bigger cams, etc, those assumptions go out the window. But if you want to follow the *intent* GM had, you have a restricted path one way and a blocked path the other way. The stock PCV does the restricted part ok, but the blocking part not so much. The check valve does the blocking part well (hopefully) but nothing for the restricted part - many manufacturers will brag how little loss their check valves have in the vac direction.
 
It's Interesting how there Isn't a common agreement on how to fix the pcv issue at hand.

So, once these cars are no longer stock, the factory PCV is out the window and we use a check valve and just accept the high blm's?

D
 
I use both and car runs just fine, passes smog with flying colors. Would it pass with only the check valve, dunno, but if it's not broken, why mess with it.
 
ravege said:
There is no one fix, one camp will say plug the pcv and run nothing but breathers. Another camp will say run a dedicated vac pump. Etc, etc, etc. What I got from Eric is that the stock ECMs are calibrated for a certain assumed vacuum loss. With ported this and that, bigger cams, etc, those assumptions go out the window. But if you want to follow the *intent* GM had, you have a restricted path one way and a blocked path the other way. The stock PCV does the restricted part ok, but the blocking part not so much. The check valve does the blocking part well (hopefully) but nothing for the restricted part - many manufacturers will brag how little loss their check valves have in the vac direction.
Click to expand...

I think there may be several different makers for the brass check valve because mine outperforms any normal pcv valve all day long. It absolutely restricts the vacuum, and absolutely seals under topside pressure. There may be different people building them differently because mine makes having the pcv in the system totally worthless.
 
Turbo6Smackdown said:
I think there may be several different makers for the brass check valve because mine outperforms any normal pcv valve all day long. It absolutely restricts the vacuum, and absolutely seals under topside pressure. There may be different people building them differently because mine makes having the pcv in the system totally worthless.
Click to expand...
Do you have any info, part number or link on the check valve you're using? I'm interested.
 
Unfortunately guys, no I don't :( If I remember correctly I may have gotten it around 2007-2008 from Bruce at Aggressive auto. You could ask him, hey may still have a line on them, although who knows where the guy he gets them from sources them. I would try Jason Cramer as well. He makes all sorts of shit in his laboratory. He may have some options.
 
I'm currently running PCV-less for the time being. Venting at the VC's. Car is not a daily so we'll see what happens. I will say when I removed my stock intake, it was brown and somewhat oily inside. Not oily like a "problem", but oily like years of PCV action.
 
I just bought the rjc pcv valve to eliminate any boost that may be getting past the pcv. I had an ac Delco prior and the car idled good and always managed a good a/f ratio. I removed the ac Delco and installed the rjc. After the install, I drove the car for 30 mins and it idled poorly, always running lean. I even reset iac and tps to make sure everything was right. I finally had to remove it and install the ac delco. Everything went back to normal afterwards. I called rjc and he sounded as if he wasn't familiar with this issue. Anyone have any ideas?

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