help! hilux 3.0lt diesel

Hi all, Im hoping that there is a mechanic on here that may help me. My hilux had a meltdown, long story. I purchased a second hand motor, same year etc. All installed by mechanic. Will not start. New injector codes placed in computer, Changed various components/ sensors to try to get it going all to no avail. I was there this morning, he had cracked a injector and turned over but bugger all fuel? anybody that may of had a problem before? maybe its a code problem 06/07 model. Cheers Dr