Hello. I am the proud owner of two RRS my 2008 I have owned for 5 years. Recently when I start the truck after sitting 8 hours or so, it rolls over good, however it almost seems to want to stall. Touch wood it hasn't yet. Once it rolls over and does this it kicks into fast idle and away we go! Any ideas as to why this is happening? Dirty fuel filter? I changed the mass airflow sensor already. Thanks in advance for help.