Get it running and smoking..
Now, 1x 1 loosen the line from the pump to the injector AT THE INJECTOR..
Look at the exhaust, did the smoke change.?? IF NOT, retighten the line and move to another.. all the while looking at the smoke..
If u find 1 where the smoke disappears, u found the faulty cyl..
U can swap the injector to another hole and do the test again..
If the problem followed the injector, there ya go.. bad injector..
If it stayed on the same hole, ya gotta dig deeper..
It could b a pump problem, a bad valve in the head, a blown head gasket, or even bad piston rings..??