Misfire and Hesitation issues when cold.

Please note it's the Supercharged 3.8 engine.

A few days ago I did some maintenance and repairs on my car including:

Transmission Fluid + Filter
PCV Valve
Fuel filter
Valve cover gaskets.
One vacuum line was replaced.

A small misfire issue popped up after this was done. Also the fuel pump went out a day later. The fuel pump was replaced and the gas tank was cleaned out. New spark plugs were installed to help with the misfire issue. Which didn't fix anything sadly.

This misfire mostly occurs when the engine is starting from cold (Upper 40's this week). Idles fine with an occasional hiccup. Mid-high throttle is when the hesitation and misfiring occurs. However when the car warms up after a little bit the car will run fine NO problems whatsoever. I have no check engine lights unfortunately.

All the vacuum lines are fine I checked for damage or a botched install and they all look fine. Spark plugs didn't fix the problem. Checked the plug wires and they all seem connected right and free of damage. I also cleaned the MAF sensor and IAC. No changes. Fuel pressure is good after replacing the failed one.

What is the next thing I should check and inspect?