1999 5.4 4x4 runs rough between 1200 & 1500 rpm
Truck runs great until I am cruising at 1200 to 1500 rpm's. Acts like it has a high performance cam (doesn't want to accelerate smoothly like the rest of the power band). Kind of acts like its starving for fuel....or air. Not sure which! Check engine light is NOT lit. Thanks for any input.