Is this engine spraying fuel out of the delivery nozzle lines? And did you remove the glow plugs so it cranks rapidly? That is how I get mine to fire up. Even on engines I never heard run before. I had a time a few years ago with a HMMWV engine I installed in a CUCV. But it eventually fired right up. Most times in about 3=4 cranks it's running. Same as the M1008 I just rebuilt. Sprayed fuel I tightened the lines and it fired right up. The glow plugs must work for it to fire. I am assuming you knew that. Good Luck.