2003 250 HPDI, History, bottom port side plug (#6 if I am correct) was fouling every few months, engine didn't like to idle on the hose, I suppose because with 2 Cylinders Already shut off at idle, a third not acting right made the engine die while trying to flush. WOT was ok, no surging or missing, but not getting my normal 5500-5600 rpm. Went through the secondary ignition, measured all the boots, and a few were at the top of the 4-6 ohm range so replaced them. Also noticed the #6 wire where it screws into the boot looked corroded inside, so I replaced that coil pack/wire, all new plugs and the engine screams, however; pulled #6 plug yesterday, after running for a while on the hose, the center porcelain on the electrode was wet with fuel oil mix, the other 5 plugs were dry and white/tan normal. Pulled compression on all cylinders and all were at 125 +\- a pound or two. So, I am thinking I may have an injector issue? I think the injector is firing, or the engine would not run as well as it does, but I think the injector may be leaking under pressure and constantly dripping fuel into the cylinder? Am I chasing the right dog here?