If your Lib is having trouble starting or you can't use the words 'stable' and 'idle' in the same sentance then it could be that your idle air control valve needs some attention.

The Idle air control valve (IACV) is a mechanical valve which opens and closes to increase or decrease the air intake after the air flow meter. It's reactive in nature, if your idle drops it opens to allow more air into the manifold.

It being a mechanic device it requires servicing, after a while the valve can become blocked/restricted with oily blowby. For this exercise we will use the following:

Firstly Locate your IACV:
On turbo liberties its located on the right hand side of the block (Looking from the front, as you would if standing looking at the engine.)

Turbo liberty:

On Naturally aspirated Liberties, its located on the opposite side of the throttle body. Its a bit of a pain to get to, but certainly possible.

The next step is to remove the hoses from the IACV. You'll need a pair of pliers to open the clamps, once the clamps are off the metal stub on the IACV, use the pliers to break the seal between the stub and the rubber hose, this will make it easier to remove the hose.

After this, you'll need to use either a 10mm spanner or socket, depending on what you find to be easiest. Remove the 4 bolts holding the IACV to the manifold. Once this is done you should be able to remove the IACV.

Once you remove the IACV, you should see this in the manifold: