I just purchased this truck back in the spring and it has ran great all summer. but now that it is cooling off it has had issues when trying to warm up. it is idling rough, missing, and sometimes stalls out. to restart i have to throttle it some to open it up. I have replaced fuel filter, fuel pump, egr valve, iac valve, coolant temp sensor, throttle body gaskets, fuel injection pressure regulator rebuild, and injector o rings. I swapped the map sensor out and tested that as well, no help. the fuel air mix is just off when cold starting, once it warms up everything smoothes out. any ideas thank you.