vacuum lines

[joe]

i have a 90 yj and have a vacuum hose attached to a red wire just below the battery that is disconnected as a result my vacuum for the 4 wheel drive does not function ,have searched but can not seem to find where it hooks up(all hoses  attached to motor on axle),also does any one know where i can purchase an upstream control valve.thks a new jeep owner.

[yjcanibul]

I have two red vacume hoses that exit their protective wirewrap under the battery ,  the first one to exit closest to firewall plugs into another vacume line that goes up over rear of valve cover ... I converted to MPI intake in '02 and at that time I plumbed it into the new intake manifold fitting ... originally it would have connected to similar area ...

The second red vacume hose to exit I believe use to plug into a round ball shaped device mounted under the battery, it had something todo with increasing vacume pressure ... anyway I removed the device accidently when installing the MPI , I ended up plugging a clear inline fuel filter into it for fear it would suck dirt in ...

4wheel works great ....

[joe]

sorry did not help as mine has only one red line ,thks anyway

[90YJGIMP]

If i remember correctly. The red line connects to a vacuum port on either the upstream or downstrean control valve.