05 Ranger . Random misfire, sometimes it's not there , others it so bad its bucking like crazy. Already replaced plugs wires and coil, No check engine light, but already did a sanity test on ECU,. Did a compression test 150 psi +/- 5 psi on all 4 cylinders. Also I have a bi directional scan tool , all sensors seem to be in the right ranges im lost , any ideas?
Also some carbon deposits on plugs.