This all started when my mds solenoid malfunctioned. I replaced the solenoid. My check engine light came on and said that there was a mis. Cycl 4. I replaced the coil and 3 different spark plugs. The dealership checked the pcm and replaced the fuel injector. A compression test was done at 3 garages, everything checked out. If I put the truck under load, the cel starts flashing. Someone mentioned a knock sensor because the spark advancement and retardation is flucuating between 08-12 degrees while idle and up to 33 degress when under load. the only cel on is the misfire.

 

I would suspect that either the mds solenoid is stuck, or the lifter isn't pumping back up.

Moving to 4th gen ram section for ya.