More rough running problems
Just wondering if anyone else has this problem or can tell me how to fix it. Engine runs rough especially when cold, until it reaches a certain rpm. I don't know what rpm because the tach doesn't read right(another problem I'm trying to figure out). I was getting on the highway after work. Got to 3rd gear and pressed the pedal to a point where it was still accelerating and held it there. The truck ran really rough but when it got that certain rpm, it's like something adds a bunch more power and it smooths out almost like it had a dead cylinder and then starts firing on all four again. I've changed the O2 sensor, fuel filter and all 8 plugs. Could it be one of the coil packs? Plug wires? One of the codes I got out of it had to do with loss of dual plug input control. Any help would be greatly appreciated!!