Help with o2 sensors

[74BroncoCO]

Paul:
1. Yes, correct.

2. If it causes an issue when I turn on the OBA, then I'dd address it then.

I took this picture a few days ago, but didn't post it as it was hard to see, but perhaps your expert eyes can see something. This is looking down with the firewall on the top of the pic, the plenum on the bottom and the drivers side to the right. The tee fitting near the drivers side goes around and back to the under side of the plenum.

 

[EPB72]

So in the last pic that hose that tees off to the lower intake with foam wrapped around it is there a pcv valve there as well?? if so one should be eliminated ..

 

[EPB72]

https://www.nloc.net/photopost/data/2668/medium/F150_Lightning_tech_PCV_hose_measurements.jpg here is a pic of upper intake flipped upside down,,,,

 

[74BroncoCO]

I'll have to take a closer look. I'm not sure.

 

[DirtDonk]

Yes to what EPB said, and yes to removing it anyway no matter what.

First off, that is not a vacuum port to a lower intake, that's an open port to the crankcase/lifter valley.
If a valve is in place (does not look it) then your metering is way off because you can't have two valves.
If it's just a hose fitting, then what you have there basically is a direct uncontrolled vacuum leak to the inside of the engine.

Perhaps not as bad for metering as a leak to the outdoors, but it's just a wrong.
So plug it off as soon as you get the chance. I know it's been running well up to this point for the most part, but I would change it anyway just to get it to the "correct" setup.

Thanks for the pic!

Paul

 

[74BroncoCO]

Well, I am not sure what I have. There is a valve in place on the lower intake that looks to open if there is positive pressure in the lower intake, or negative pressure in the hose. So is this wrong?

 

[Timmy390]

The 5.8L GT40 Lighting and the marine version both have a PCV in the intake same as the GT40 lowers for the 5.0. 99% do not use it because of massive oil loss even with the correct screen installed and the baffle on the bottom of the intake intact.

I tried using it only to have bigtime oil burn. I went to a system more like the original trucks/cans had with the PCV in the valve cover. I pull metered air in from the intake hose intot eh engine at the fill tube and then out on the other side valve cover into the intake. Clean, no T's and how they did it from the factory. No more oil burn

Tim

 

[DirtDonk]

Yep, that's a second PCV valve. So you need to cap one of those off 74. You can use either one, but I'd take Timmy's advice and just continue to use the one in the valve cover like you have, and close off the intake one somehow.

You can find something to plug the big hole, or just re-insert the existing PCV valve and cap it's hose barb/fitting with something reliable that can live a long time on the back of an engine.
Normally I say don't use the common vacuum caps, but since this is not a vacuum leak area, you can probably get away with it.

As said, just run a single hose from your valve cover PCV to the vacuum port on the upper intake. The one you're showing in the lower is NOT vacuum.
The way you have it now, the engine vacuum is sucking through 2 PCV valves, so is not being metered properly. It's not killing anything inside the engine, but it's not working as programmed.

Paul

 

[74BroncoCO]

Gotcha! Thanks. Will source a plug of some sort an clean up routing of hose from PCV on the valve cover.

FWIW - I did check that the firing order is 1-3-7-2-6-5-4-8. That matches the dist. and the wires. There appears to be no cracks in the accordion tube.

Now I need to go thru my receipts and see what cam really is in it.

 

[Timmy390]

Rubber vacuum caps are junk. Mine failed in 2 years resulting in huge vacuum leaks I had to track down. I've switched to vinyl caps. All the parts stores have them.

As for plugging the rear PVC, I used the valve and attached a small/short hose and put a PEX plug in the end of the hose. Worked......

Tim

 

[74BroncoCO]

It appears to be 3/8" ID? So I could source one plug for the lower intake PCV, then just remove most of the hose and route the valve cover PCV right into the under side of the upper intake? Seems easy.