I have a 93 F250 5.8 . The motor is idling rough like it has a dead cylinder. I changed the plugs and wires also the cap and rotor. The truck sits around and is not driven on the road, just use it to plow the snow when ever it snows. added some injector cleaner in the gas tank and ran it empty,still running rough. It seems like a injector is bad. Checked the codes and only coming up with a 538 with is no help to me. Is there any idles on what to look at next

 

Yep injector, or connection sounds certainly possible. Compression test?? You can check code in tech info at top of forum, I already looked, something about RPMS insuffficient during test etc. user error. Good luck. I'm sure some others will chime in.