My 2nd hand XJ came with an unconnected airbox on the intake side. No hose can be found at all.

Should I worry about it? Does it affect fuel economy, or will the engine just suck up the air through the hole anyway?

Here is a pic:

 

That's all there there is, hole in side of box

 

There's a thermostatically opened damper that goes in there. The damper connects with an air duct to the engine. When the engine is warm, the warm air goes through the duct to open the damper. It's supposed to keep cold air from entering the air box until the engine is warm. I think it's more important in cold climates. If it's warm where you drive, it won't matter to be left off.

 

...are you referring to the big square in the bottom of the air cleaner, which is how the engine gets its air?

 

As designed. You'll see the intake line coming from the box to your throttle body above where photographed.

 

You could fabricate an adapter to move the air intake location higher to improve fording.

 

iF THERE IS A "FLAPPER" there, my son's XJ doesn't have one, nor have I seen one in any pics I've seen on here, no any mention of such during CA, cowl, or snorkle mods.
If such a beast does exist, please post a linc to such.

 

I assumed that was what he meant. I don't think they would have left it off at the factory. I've never seen an XJ with nothing there but as I said, if you lived where it was warm, a thermostatically control air damper probably isn't needed.


It's at the position called "vacuum motor" in the pic attached.

 

Posted. These were harder to find than pictures of the Loch Ness Monster. I'm assuming people have just removed them since if the damper was seized closed, it would block flow into the airbox. Maybe it's only a "cold weather package" deal if there was such an option.


Here's some pictures (not mine) so they do exist both with and without the vacuum damper.

 

It was the square hole I was referring to indeed.

Since I am in Australia, I should be good, even without the vacuum damper?

 

I believe the heated air intake is a only used on Renix and older models (Cruiser?). Newer models just have a square hole in the bottom of the filter box for the intake. Both my '99 and my '95 are setup like that.

FYI, squirrels love to stash stuff in there.

 

Not only do the later models usually not have anything attached to that hole, at some point they also closed the hole in the steel panel directly in front of the hole in the box. If you look at older models, there's a rectangular hole there to let cool air reach the airbox. On my 2000, that panel is completely solid. If you put that airbox with the extended intake pictured above in my XJ, the extended end would be flat against the steel panel so that no air would come in at all.

A while back I found a 2.5L XJ in the junk yard that had an attachment on the airbox that wrapped around the side to take air from right next to the exhaust manifold. I have to assume that was some stupid emissions thing.

 

Doesn't exist on later models. Early Chrysler versions had just a straight tube, I've seen as old as '94 at the junkyard with absolutely no provisions other than the big hole.

 

I would think so. I think a coarse screen on the opening wouldn't hurt and probably keep the beasties out of the air box.