1985 300D Turbo IP valve 1 and 2 not pumping fuel
 

Hello,
I have a 1985 300D Turbo and the injector valve on the front two valves (1 & 2?) are not delivering fuel to the Fuel Injectors.
I figured this out by first cracking the fuel lines after replacing my filters on lines 1 and 2 at the injectors. when I saw no fuel getting to those injectors I then cracked the lines at the IP itself and no fuel is coming from those valves.
I get plenty of fuel from the back 3 lines but none from the 1st two and therefore my engine won't turn over. it just turns until the battery eventually dies.
any ideas on how to fix this?
Is my IP dead?
Thanks for your help!

Thanks so much ForcedInduction. This is very helpful.
Quick question regarding your response.
Once I get the pump plunger in place and test to see if fuel flows into the element,
what is the diagnosis if it is/is not?
Thanks again!