My truck will start and run rough untill the engine is completely warm. I can start the truck in the morning and take off and floor it and only get 1000 rpm's and I have to baby it to warm it up or it will die. I have to sit in park and rev the engine up and hold it just below 1k but do not let off because it will die for sure. This started about a month or two ago when the weather kind of changed where I live. But we just had a good 3 or so days of 70 degree weather and it still did the same thing. I had one person tell me it was normal due to the cold ambient pkg(CAP) and the exhaust back pressure valve (EBPV) being that when the engine oil is cold the valve will close in the exhaust the build up pressure in the engine to warm up faster. If this is the case then why did it do it when I had my truck sit in 70 degree weather for 4 days or why woudl it do it after the truck was running for awhile then I let it sit for 6 hours and it does it again? Does anyone know how to fix this problem? I am at the point where I have to let my truck warm up for like 30 mins and I can not let it warm up on its own or it will die. I have to sit in it and baby it for the first 10 mins or so and then I can let it idle to warm up. Anyone?????