air box vacuum lines?

I'm not sure if I should be posting there or the modified thread but I'll try anyway. I have a basic stock 1990 XJ that I am looking into putting a Airtube intake from Rusty's. Its a simple install but they say trace the vacuum lines that go from back of the air box to the intake and plug them. But it looks like the vacuum lines control the EGR valve, so im kinda dumbfounded at this. Can anyone help me out and explain this to me?

lines from intake to air box (thermal switch and warm air butterfly) SHOULD be a separate port on the vacuum tree than the EGR solenoid vacuum line. They run parallel around the front, but are not supposed to be connected anywhere.

The two small vacuum lines at the rear of the airbox are for the "thermostatic air cleaner" - essentially, the preheater for intake air. If you look at the front end of the airbox, on the snout, you should see a vacuum actuator on one side and a corrugated tube on the other. The corrugated tube goes to a heater wrapped around the exhaust manifold.

The two lines go into a thermostatic switch, which opens and closes the actuator according to air temperature.

I'm not entirely sure what it's supposed to accomplish, if anything, but it can usually be safely deleted without harmful effect (else they'd not get approval for deleting it on the CAI kits.) It had some utility on carburetted engines, but not so much on PFI setups.

The EGR lines should not go anywhere near it, those are run through a different vacuum circuit.

thanks a lot for the help. I finally understand what i was messing up, it was the fact that the vacuum lines run parallel to each other and i kept mixing them up.

verticalspark said:

thanks a lot for the help. I finally understand what i was messing up, it was the fact that the vacuum lines run parallel to each other and i kept mixing them up.

Click to expand...

If it's the airbox lines, it doesn't matter which one ends up on which side. It's not a check valve (one-way flow) back there, just a thermally-controlled 'on-off' valve.

Actually I just realized that the hose for the thermostatic valve was never there. So I took the air box out and decided to make some modifications to it instead of buying a new filter and the Airtube. I cut off the thermostatic valve and cut some more holes in the air box with a pneumatic windshield removing tool to help it breathe better.

http://s127.photobucket.com/albums/p123/verticalspark/

I think you have just built a warm-air-intake. It's going to pull in a lot of hot under hood air instead of the (somewhat)directed cool air from in front of the vehicle.

x2 that. The last time I had the air box off, I deleted the warm air intake. I do get a shudder on occasion during warm up, especially under 50 degrees. It doesn't last long as the engine warms.

Getting cooler air from somewhere other than under the hood is nice - and the better performance air filters include a "air dam" block off to only allow cool air from behind the headlight to enter.

It's why I won't use an open element cone - you have still have to use an "air box" to get cool air. I'm back at working on the 5.0 HO Mustang air filter conversion, found a large MAF aftermarket adapter will bolt to the cleaner. One more step.

ha ha ha