I'm going to change the plugs and see if that makes a difference. I installed the Plat fours a while ago. I'm going to substitute thePlat fours for the factory champions.

 

I think it's suggestive that only the right side of the engine is misfiring.

Not sure what it means though.

I very seriously doubt it's spark plugs. How fresh are your O2 sensors? As I recall, Jafir had a similar misfire problem that was solved by new sensors. I don't remember if the sensors were throwing codes for him or not.

My other thought is an electrical problem. The injectors get + from the fuse block and - from the ECM, but I'd check to see if the passenger side cylinders all get + from the same wire. A short in that wire could create a misfire on 2-4-6-8.

 

Update:

Ambient 42F

Started fine this morning. Got it to my dads shop with intentions of swapping out the passenger side motor mount. Turns out the drivers side is completely busted too. So, that job is on hold.

Anyway, I found the negative battery cable to be really loose on the battery terminal. I'm hoping that was my issue.

I guess I'll find out tomorrow. Temps hitting low 20's.

 

The saga continues...

Ambient 27F

No start this morning. Thinking I should replace the Rotella 15w-40 w/ Rotella 5w-40

 

You the man! It was the fuel pump relay.

I switched the fuel pump relay w/ the washer relay and it fired right up. Switched the relays back and it did not start. Switched them back and it started. Switched them one more time, and no start!

Not sure how this ties in with cold mornings.

 

Good news! Glad I could help. The fuel pump relay is one of those less common problems that bites a few of us in the ***. It doesn't help that the symptoms are almost identical to CKS failure. Relays are mechanical devices, so I'm sure the cold is just making the relay stick. Another trick would have been to tap the relay while someone cranked the motor, which might have helped it break free and actuate.

I would definitely be running 5w-40. Most engine wear happens when you first start the truck, and the oil hasn't lubricated the engine yet. At 27 deg, 15w-40 is gonna be so thick it will take seconds longer for it to start effectively lubricating. In terms of engine wear, there is no disadvantage to running 5w-40 year round. Even in the summer it will lubricate the engine faster.