Whiteboyz71

What's up guys, hopefully somebody has some insight to my issue. I have a NNBS 07 Silverado CCSB that I had the AFM/DOD delete done on a while back, truck runs great. But, I tried installing a Moroso catch can today and it did some weird things while idling. My 5.3 is a gen IV and the lifter valley cover was replaced with a vented one when I had the AFM/DOD delete done. I capped off the fresh air line on the passenger valve cover, plumbed the driver side valve cover inline with the valley cover using a t-fitting then to the can, off the top of the manifold to the can & modified the factory oil fill cap with a breather filter, no valve just a valve cover breather from the parts store.

This is how I routed the system.


I'll post a couple vids of how it acted at idle and with just a blip of the throttle with the vented oil fill cap and one with a sealed oil fill cap and another of a sucking sound it made shutting it down with the sealed oil fill cap. It threw the check engine light during these tests and I'll have it scanned tmrw to see what it says. I put the system back how it was with just a filter on the driver side valve cover and the fresh air line on the passeneger valve cover and vent off the valley cover plumbed together with a t-fitting and breather filter making the system open to atmosphere like it was before I tried installing the catch can and all is back to normal minus the check engine light.

Whiteboyz71

Video 1 with the vented fill cap. You can clearly hear a ton of air being sucked through the filter at idle in person. BTW, it did not have that lope to it with the system open to atmosphere and sealed oil fill cap, only after installing the vented oil fill cap and catch can.


Video 2 with the sealed oil fill cap.


Video 3 sucking sound while shutting down with the sealed oil fill cap installed.

Whiteboyz71

Also in the first video, I was not holding the RPMs up, it did that on it's own. My first thought was getting a valved oil fill cap that also has a breather on it, like the ones CFM Performance and UPR offer.

https://www.c-f-m.com/performancepar...=0&VS2=0&VS4=1

Whiteboyz71

Thoughts anybody....

badbowtie15

I think you introduced a major vac leak with that breather cap. On a N/A setup, leave the clean side stock. So I would put the hose back in that goes from intake tube to pass side valve cover.

Atomic

iTrader: (42)

The first video is because it is drawing in a lot of unmetered air, basically you have a big intake leak. It lopes because it is running lean and the fuel trims havent added fuel yet. It hangs because the air trims havent taken air out to where it should be because of the leak.

If you insist on keeping the sealed can, you need to put the fresh air source behind the MAF, but you also need a check valve to make sure you dont get reverse flow under boost, and you also need to make sure you somehow vent the crankcase pressure under boost to somewhere other than the intake (so, to atmosphere).

You need to get a catch can system designed for boost with check valves and breathers and all that, or eliminate the MAF and just run an open system at that point.

BigKID

iTrader: (5)

Presuming this is a n/a setup and you actually want a vacuum sourced pcv:

-remove breather and reinstall fresh air source from passenger valve cover to intake tube
-Connect valley cover directly to top of can, remove tee to driver valve cover and cap pcv valve. (this is for simplified setup, you can leave both to top of can)

This will provide proper metering of crankcase air circulation.

If boosted, disregard, you will need to reconfigure with check valves as mentioned previously or leave everything open to atmosphere as you originally had it.

Atomic

iTrader: (42)

Ah, yea youre right, I glanced and saw the exhaust wrap and thought it was a turbo setup.

Do what ^he said

Whiteboyz71

Shoot I wish i could afford to do a boosted setup Be a beast of a CC Z71.

BigKID, I would like to keep the driver side valve cover plumbed inline with the valley cover.

Thanks for the help guys, this is why I like forums, well GOOD forums. I'll report back after I get it reconfigured like mentioned above. Also, I'm assuming the code that threw the check engine light is going to tell me there's a vaccum leak (the breather fill cap sucking air was my first thought yesterday) I'll have it cleared & it should be good then.

Whiteboyz71

The codes it threw were banks 1 & 2 lean, just like you guys mentioned. Got it rerouted like BigKID suggested, but keeping the driver side valve cover plumbed inline with the valley cover and all is good up to this point and she still has a slight lope to it at idle now with a stage 1 BTR cam.

Thanks again.