This is how I deal with a tight Injector. (Use 1/2 inch drive stuff; 3/8 drive will be too flexiable.)
Steady with your Right hand and keeping you Left Arm Straight bend back and pull back with your Shoulder in a quick smooth (do not jerk it) move; you can even take a short step back if you need to.
Also, pumping on the hand primer will not bleed/clear the air out from between the Fuel Injection Pump and the Injectors.
To do this you tighten down the Injector Hard Line Nuts by hand and turn them back to loosen them alittle. Afterwhich you crank the Engine you till you see Fuel coming out from under all of the Injector Hard Line Nuts.
After that tighten the Hard Line nuts and start your Engine.
Also it is very easy to get dirt in the Injectors.
84 300D, 82 Volvo 244Gl Diesel