Little vacuum hose

[87Chief]

I took the vacuum hose off from back of my valve cover... I plugged it with my finger, my engine doesn't shake as much. Like it runs better...

 

Is it a good thing?

[tugalo]

not a good thing...that vacuum lowers the pressure in the block and helps prevent oil buildup in your air filter....

[64 Cheyenne]

Possibly too large of vacuum line?

 

Like maybe somebody put too large a line on trying to cure oil puking into the VC.

 

My friend did this, updating his VC and vacuum lines, drilled out the fitting on the plastic VC

 

grommet to 1/4". more is not better in this case. He replaced the grommet drilled out the hole to 3/16

 

runs fine. The CC needs vacuum on that line but not too much as to cause the engine to run like crap.

[87Chief]

See, I put a 91 YJ valve cover on, and I was testing to see if it would leak or not... It doesn't ( :thumbsup: ) but now i'm trying to figure out what I do the hoses, I'm not sure what the big one is for either, the hose itself is in rough shape, but the plastic vacuum hose I'm talking about is pretty big but too small to fit into the YJ valve cover...

 

The Yj valve cover has a hole in the back too big for the hose that was on the front of the Comanch's VC, and vise versa....

 

What should I do?

[64 Cheyenne]

The big hose in front goes to the air box. I replaced mine with heater hose.

 

The fitting on the back of the VC goes to vacuum. You need the proper grommet for your VC

 

then plumb it to a 1/4" fitting on the intake and you should be good to go.

[87Chief]

Ok, this is the valve cover that is on...

 

 

The big hole in the back is where the vacuum goes? And the small hole in the front (next pic) is where I need to put the hose from the airbox?