Help Needed on cylinder 3 issues

Good day to All MazdaSpeed Family. I have an ongoing issues with my 06 MazdaSpeed6. Little background : I travel for work allot. Hence my car will do more sitting that driving and it has little over 36k miles on it. Came back from work, started my car and took it for a drive. About an hour into driving car started stuttering and bucking at time. But then it will pick up again and work fine. Took it out for another drive the following day and it was bucking 5 minutes in... It limp its way back home. Did some checks and it was running rich. Had to leave for work again so I did not get to do much to it. Came back home did some troubleshooting and changed relief valve on the fuel rail, took apart HPFP cleaned it upgraded the rubber seals to handle Ethanol and changed the ITFP as well. I also changed the spark plugs and Coil pack with NKG. It started right up drove from driveway and it struggled to get back into the driveway. Did a compression test. Came back great. But I'm checking the plugs, 1, 2 & 4 had little build up on them but 3 looks brand new. I have done continuity test from that plug on the harness to the ECU, the relay in the engine bay, the fuse in the engine bay and also to ground....... Any other suggestions on where I can check or do to resolve this issue.

 

Have you tried swapping the coils from one cylinder to another to see if the symptoms follow the coil? What is your spark plug gap set at

 

Spark plug are gap between . 026 -. 028...i have change coil pack around as well as reinstalling the original OEM.. Then putting the NKG coil packs back in. I can recheck the gap on that cylinder 3 again

 

Check all of the connectors for cylinder 3 separate every connector and make sure that all of the pins are lined up and haven't been pushed out

 

Good day... I have check the pins for the coil pack and did continuity check on the three wires from the connector of #3 cylinder. The only thing I have not check is anything dealing with fuel to that cylinder... Thank you much for your help.. I hope you have more ideas I can use.

 

I actually still have the wire harness for the coil pack still out... Making sure all is well with it before reinstalling it