I have a 00 3.5 trooper. Summer mornings starts at 2k rpm then goes to 1200. When hot in the afternoon it starts at 1800 and goes down faster to the normal 1200 or so. So the coldee start ups the higher the rpm iv noticed. However I have 3 digital Throttle position systems. 1 i got with the car that ran higher and kept giving me a error code i and made it sluggish with low power. I got my 2nd TPS from a 3.5 rodeo and its the one im currently using without problems. Then my 3rd i bought new and idle starts at 4k+ rpm but i kill it before it goes higher. Figuring out these need to be adjusted by a mechanics computer. . I also cleaned the entire air intake system and throttle body using proper CRC cleaners and it ran a little smoother.