Matt16

In this picture, the hose has been replace by a (red) breather. I know its emmisions stuff, and wasn't on some earlier trucks (my wrecker 1988 air box doesn't have a connection). My truck has an after market air filter with no connection for this hose (goes from the black bulb under the intake to the airbox), so the previous owner left it open. I want to know if there is any way that unfiltered air is going into the combustion chambers and scoring up my cyl. walls.

iamsuperbleeder

that dirty motor looks familiar

I put it on there because I just didn't like the idea of a gaping hole considering the tube that was on it lead straight from the air filter box after the air was filtered...

just insurance... and it looks neato!

but honestly, I don't know if it neccesary; I know some have even bypassed and removed the black plastic thingamajig down there (couldn't tell you what it is for the life of me )

Matt16

You'd think the lazy sod owner would wash the thing once in a while. Maybe there was lots of new additions to youporn that day

iamsuperbleeder

maybe... I'm not going to deny that

I'm just waiting till the motor swap, cause after that the truck will NEVER get beat on and sunk un the mud like it use too... at least not without cleaning it afterwards

toyota4x4907

It goes to the PAIR valve. Pulse Air Injection reed valve. The black "bulb" is the resonator. The venturi effect of the exhaust gas pulls air from the reed valve, which comes from the tube you are wondering about, to speed up the cat converter's reactions. The copper-looking tube on the top of the exhaust manifold is part of this system. that tube snakes around the rear of the engine to the reed valve. It IS part of the emissions.
No unfiltered air should be able to reach the combustion chamber via this routing. No filtered air for that matter should be able to reach the inside of the engine from this system.

Matt16

Thanks. That's the answer I needed. So unless I've got a really badly burned exhaust valve driving through really dusty conditions there isn't a guy-in-a-white-hood's chance in Harlem of getting dust in the combustion chamber. I guess the air is filtered so you don't get mud in the cat.

toyota4x4907

Even then I highly doubt any air will travel backwards up the exhaust ports. I mean, I don't know for sure, but to me it seems highly highly unlikely.

Matt16

I agree that it is far too unlikely to worry about.

toyota4x4907

lol.