Weird warm up after egr ****** & oil cooler

I've noticed after I did ****** and oil cooler after truck sits over night it has to warm up or it has no power, almost like its lost prime. After 30-45 seconds of warm up it runs fine but before that it won't even pull itself. Any idea where to start?

Does it run rough? Did you JUST do the oil cooler, meaning you introduced air into the oil system?

I did the egr ****** and oil cooler, I drained the valley the oil cooler sits in and drained all of the truck oil and did an oil change. Truck has been driven roughly 1,000 miles since then though I would imagine all of the air is purged.

Gotcha. I wasn't sure if you had put any miles on it after the oil cooler to work the air out. You need to get it on a scanner. Check ficm voltage, check for injector codes/do a power balance test, and check your ect/eot sensors, before you start the truck in the morning, and see of the sensors are reading close to the outside temp.