Okay so first off, i have a 4.0 OHV, i have 0 intake leaks , have thoroughly checked that. 02 sensor readings are that of good sensors, crank position sensor is new, cam position sensor/ synchronizer are new, fuel injectors are recently new, IAC is new and MAF is new. No i wasnt just throwing parts at it trying to fix it, the engine is actually from another ranger and when i swapped them i replaced a bunch of stuff that had aged while it was easiest but when I go to accelerate from a stop I get a gnarly hesitation that feels like the engine is about to stall then it runs perfectly after and no signs of problem until I stop again. Fuel trim looks normal until i accelerate and in high rpms goes all the way up to 20%. Do i have a cracked head or does anyone have any idea what else this could be? Will be testing fuel pressure tonight but I have a feeling it's not the pump. Thanks in advance and MERRY CHRISTMAS YALL!