This is my third posting on the continuing saga of a misfire developing after rebuilding my transmission on a 1999 Dodge Ram 1500. After a new crank sensor, timing chain, cat, upstream O2 sensor, fuel sync, distributor, rotor, wires, plugs and swapping injectors I was about ready to replace the PCM. I posted about a NOID lite not puslating, staying on and began checking for a short. #6 was the only injector not pulsing. So I started at the PCM. 5v wire goes to #12 spot of #2 PCM connector, ground to #12 of 3rd connector. I found if I unplug the #3 connector I would get a short registered from my DVOM. If I left # 2 and 3 connector plugged in and removed #1 the short went away. If I left #3 and #1 connector plugged in, no short. With #1 and #2 plugged in the short showed again. So I figured it wasn't the ground wire. I started pulling fuses and relays, one at a time and testing. When I got to a 15a fuse for the O2 sensor the short went away. I put the fuse back in unplugged the upstream O2 snesor and still a short. Plugged in the upstream and unplugged the downstream still a short. Unplugged both and no short. More wire to trace but why this is only affecting the #6 cylinder is a mystery to me. Anyone ever run into something like this?

 

The injectors are individually controlled. (sequential fuel injection, as opposed to batch fire) So, it is possible that just the one wire is damaged, and causing your trouble..... Time to trace that one from end to end....