new injectors/how to bleed system?
 

just installed new injectors on the 1984 300DT. how do I properly bleed
the fuel system? I'm getting fuel at each injector, but the hand pump has
absolutely no resistance? feels like I am just pumping air.

Have you tried cranking the engine with #1 injector hard line nut cracked.
If you have fuel at the injectors it should eventually clear of air and fire.
No resistance at the primer I am not so sure about.

The primer pump will get get fuel TO the IP, not through it.
Crank away to get fuel to the injectors, has to fill up the rack too.

The primer pump only fills the IP and filter. It won't prime the lines or injectors. Just crank the engine over until it catches. Or you can crack the lines open at the injector and turn over the engine until you see fuel coming out. I usually just leave them connected and crank it over. It won't take too many attempts to get it started.

You should be getting resistance and a squishing sound out of your primer pump. If you aren't you either still have air in the lines or the pump it shot.

ok, here's the story. I bought new monark nozzles and had a local diesel shop bench test and install them onto the old injectors. replaced valve stem seals, valve springs and new locking cap nuts. then, adjusted the valves. finally, installed the injectors with anti seize and torqued to spec. the car starts and runs, however it has a knocking or clicking sound somewhere in the vicinity of number one cylinder. started the car and drove it around the block. however, the hand primer pump still feels like it is pumping air. should I crack the all the injector lines and try and bleed the system again? any ideas on what may be causing the clicking or knocking sound?

You could have a valve that is adjusted too loose.

You can also swap injector postions to see if the tapping follows the swapped places.

thanks for the advice. it just seems weird that the hand primer pump still has zero resistance. I'm thinking of rebleeding the injector lines one at a time and then trying to bleed the system using the hand primer pump again.

The hand primer only primes up to the IP, not into and through the IP.

Do you have the old style or new style hand pump? Old style unscrews and then you pump. New style you just pump.

The old style ones are notorious for leaking and should be upgraded. They will leak all over your motor mount and destroy it. They aren't expensive.

Scott

now that you mention it, I have the old style that unscrews. I'll be sure
and check it for leaks and upgrade it very next parts order. thanks.