Misfire on jeep comes and goes? What could be the cause of this issue?

I'm stumped here,For two weeks, the engine would work poorly, misfire, then go away just like that. You need to give us more info to put it together is to how it can blow 2 engines, this is a weird one-

Here is more info. For two weeks prior to my engine blowing, I would start the car and it would misfire and idle very rough. Then I would shut the car off and restart it and it would be fine. Sometimes the engine light would come on and sometimes it would not. Then one day I started the car first thing in the morning and the engine blew. I paid for a new engine and just got it back and it has already started to do what it did with the last engine. Saturday for instance it was great for about an hour, then it started to misfire and the engine light went on. Sunday morning, I decided to see what would happen if I started the jeep and it was fine, no misfire at all. So that is where I am at with this issue.

Okay-lets have the computer scanned for code/s if any present post them-

p0302 cylinder 2 misfire

Check sparkplug, compression and injector for cylinder no.2

I had the injector changed which is what they said the problem was and that didnt change it. I also had the computer changed cuz thats the other thing they said was the problem and that never changed it either.

When the engine blows both times, what are the damages?

Ok. We have 2 different engine in the same vehicle experiencing the same problems.
What wasn't changed when the engine was changed? Fuel tank: Was it flushed? Not terribly likely that contaminated fuel would cause a problem in a single cylinder, but possible.
When you say "the engine blew", what exactly happened? Did it freeze up? Through rods? Bend valves? Blow a hole in a piston?
Knowing exactly what happened can really help us determine what the underlying issue is and how to correct it.

Happy Thanksgiving!
I do not really know what happened to the engine, but I'll tell you something interesting. Yesterday I paid a guy to come and check out my car. He said that fuel is entering the cylinder and lowering the compression. So he freed is yesterday and the compression went up. I started driving it and it was great again, then slowly you can feel the jeep running rougher and rougher. Yesterday when I stopped at a couple of stops I could smell gas a bit (which was also the case the last time). Today when I started it it was back to misfiring and the engine light flashing. The guy that came over yesterday also said that there is a small evap leek. Thank you for your help

Have the fuel pressure check-injectors could be leaking or excessive fuel pressure, clogged return line

Also get the leak in the evap fixed.

Thank you for your help, I'll fill you in tomorrow when I get someone to check it out.

I'm thinking why your engine is blowing up or whatever the case maybe-its probably the injectors are leaking so bad and washing up the cylinders wearing it out and compression will not be develop to produce power-

Yesterday the people that I bought the new engine from sent someone to inspect the vehicle. The guy says that the computer needs replacing and thats why I'm getting random misfires on a couple of cylinders.
Today however I paid for my own electric specialist who came highly recommended, and he says that 2 of the injectors are not working and that the injector wires (coils)are old they should have been replaced long time ago. He says that if I change those things, the engine will work well. My thoughts are that it sounds right, cause when they changed the computer I still had the problem.

Your thoughts Please?

I guess we'll see what happens when the injectors are replaced-

How's it going with this vehicle jeeplibertypaul?