Sorry to hear about your problems. I felt the same way after getting mine home and starting to clean it up. I am pretty sure the seller pieced my jeep together from parts, because I am finding things from multiple years all over it and lots of things broken that he said were working perfectly.
For example the A/C blew cold as ice when I bought it, but after 2 weeks was dead. I was pretty annoyed and have attempted to fix it, but it still leaks slowly. Also, the valve valve cover gasket leaked like crazy, but was pretty clean on initial inspection. He had obviously cleaned it up before I looked at it . Unfortunately the list goes on. It is ultimately my fault because I did not inspect it close enough, but it was my 1st Jeep and I honestly just got excited and caught up in the purchase. He seemed like a nice guy too.......
On the bright side, these things are pretty simple to work on, and fit together like the automobile version of Legos, so having parts from multiple years is not a huge deal. This forum was a huge help and has really knowledgeable people who are willing to help, so take advantage of their knowledge for sure. Just get it to running/driving order and once you are a few months past the hurt from the lies you will love it and the little problems will not seem like such a big thing. Just take your time and fix them as you go.
Hey don't feel bad.
I have had seven Jeeps but my TJ is the first one I've purchased in 25 years.
I paid over $20,000 for a low mileage Rubicon, and nearly twisted my arm out of socket patting myself on the back.
2 regears , 4 tires , windows , fluids , u joints , unit bearings, a new crappy lift to replace the crappier lift , shocks , and tons of this and that...
Now I've got a pretty nice TJ, most guys on here would have 2-3 for what I spent .
Some of it was just getting excited and not paying attention to the aged condition of the vehicle.
Some of it was ignorance, not knowing what to look for.
And some of it was getting all excited over big fat tires and the look of it ...
I didn't make the right decision but at the end of the day I tried to make the decision right.
Anyway enough with my stupidity... If the thing's not rusted out, and if you didn't pay a ridiculous price, it's probably going to work out pretty good and you can just about bet it's going to be a ball.
Sometimes we give Jeeps a bad rap.... Show me any vehicle that's designed for off-road use and is 13-22 years old ... Most likely that vehicle is going to need some work.
The 4.0 was chosen for the Tj probably because they had the tooling and production set up , it works good in it , and the market loved that engine .
It is long way from today's engines, but it's tough and reliable.
Hang in there and stay on here and work the bugs out of it ..you may find it to be one of the favorite vehicles you've ever owned.