We have a 2005 Granite with a Mack 10 speed. It pulls pretty decent when it finally takes off. It seems like it is waiting to see boost before it gives it more fuel, then pulls decent. When shifting it goes flat for a few seconds. When up shifting it is not as big of a problem. Down shifting when pulling a hill it sucks. That period of no power seems weird. We just bought this truck, and it is the only one with this engine. Our others are E6, or MPs. It’s not like a dead pedal, just very weak for a couple seconds and then starts to build power. No lights on dash, no smoke. Truck is out of Canada if that makes any difference. Yesterday was first trip with it so maybe I just need to drive it differently??
