I purchased this car a few months ago because the transmission wouldn't shift. I got that fixed but I cannot figure out why it idles so poorly. I have replaced both fuel filters and O-rings along with the clear fuel lines. It starts great without any smoke but quickly starts idling so poorly I am surprised it stays running. I also ran 2 cans of diesel purge through it. I am getting a P0300 code (random misfire). I took it on a 500mi round trip this weekend and ran smooth on the highway getting over 30mpg. I am going to have the injectors cleaned. Does anyone have any ideas before I starting throwing money at it?