· Premium Member
Does anyone have any advice, hopefully backed by experience, regarding the rechipping of a 14CUX, 4.2? I have just finished a scratch built 4.2 to replace my tired 3.9, and am hugely impressed by the performance gain, especially low end torque. As all 4.2 engines were originally only used in Auto Rangies, I am curious if there is a reccomended upgrade for that computer when used on a manual box. Idle is slow to flatten when off the power, but I hesitate going back to the old computer as I'm guessing the fuel mapping is different for 3.9.