I just bought the heat shield kit off amazon with fuel rail, injector, and bottom heat shield protector too! There is actually a TSB out on cylinder 3 injector because I guess it is too close to the manifold and fuel vaporizes! That will from what I read also tear up that cylinder so I did a compression test and cylinder 3 is low........between an older engine 15 years old, 125kmiles, low compression on a cylinder, somewhat worn camshaft, looks like a new motor at some time soon! Thanks!This is a super long shot, but I've got an 05 TJ 4.0. I've got 110k on it now, but I was having issues somewhat similar (P0340) and randomly ran like someone suddenly dumped water in my fuel. I chased parts, was at my wits end, and a local Jeep shop said to look at getting a new fuel rail heat shield etc. I'm in Texas, so Hot like MS brother, and it happened in the heat. The fuel in the fuel rail will boil, you get vapor lock and start throwing codes etc and running like crap. I put on something like this and problem was solved.
For the amount of money and effort, may be worth a shot.