1998 Limited AC Progess, but still trouble

So I'm in the same boat as a lot of fellow XJers trying to get my AC to work correctly during the summer. I have a 98 Limited and I have partial operation with my system. I first suspected the low pressure switch after posting here initially and getting some great advice. I replaced the low pressure switch but the problem persists. The compressor only cycles on briefly and then stops. When it is working the AC blows COLD so I know its working somewhat. I'm not getting any water below the Jeep so then I suspected a plugged drain. I pulled the drain hose off the firewall and carefully inserted a coat hanger to see if there was an obstruction. Nothing came out and the hose was clean. My next idea was to try topping off the freon. I bought a bottle from my auto parts store with a built in gauge. At first I couldn't get the system to take freon because the compressure wouldn't cycle. I waited about 4 hours and tried again and the compressor cycled on great. The system took the entire bottle, but the gauge shows good. Now, the system works about 70% of the time instead of 30% so I'm on the right track. My question is this: Do I continue adding freon or do I bite the bullet and take it somewhere? I don't want to overfill the system and I assume the gauge on the freon kit is accurate. Should I try another bottle ($26)? And if the system requires that much freon should I be suspect of a leak? The bottle was 18oz.

Thanks for your time and any thoughts you might have

Thanks for your time?

I would add another bottle, or buy gages. Harbor Freight has them pretty cheap and they worked OK for me. Your 98 works on R134, right? I get that at Wallyworld for about $10 IIRC. To keep the compressor on with a low charge, you just jump across the low pressure switch. When the bottle starts running low, I put it in a bowl of hot water to get more out.

yeah, it really sounds like you are just low on freon. I think it takes 36 oz or something to fill it w/ freon (don't qoute me on that). I wouldn't trust the gauge that came with a bottle of freon to be all that accurate. Go to autozone and rent the nice guages for free. Buy a bottle of freon (walmart sells 12 oz cans for $7) and even get yourself a can of leak detector and put that in. If adding freon made it start coming on more, I'd say that's the problem.

When it's low on freon the compressor will either not cycle on at all or very briefly. As the freon level gets closer to what is needed it will stay on longer. It should still cycle when it's full, so don't expect the compressor to be running all the time.