1979 300d hard starting
 

I have a 1979 300d,Ive only had a couple of weeks ,I do know this.
1 the glowplugs work and glow bright orange
2 there is voltage going to glowplus
3 I have a electric fuelpump,so I know the injector pump is getting fuel
4 I have to crank for about 20 seconds before starts,and even then I have to push on footfeet to keep running ???????then it will idle
5 turn engine off go to Menards ,do a little shopping come out ...hard starting again,and the engine is warmed up.

When was the last valve adjustment done?

1. if one plug is bad then none will work
3. no you dont

When the car is running is it running smoothly and no smoke?
What is the highest pressure the Electric Fuel Pump can put out?
What is your Engine Mileage?

Is your fuel pump an auxiliary unit?

how much oil are you using? my 240d has the same issue -but no compression! and really gulps oil! my solution is swapping to a euro 300d

yes the car runs smooth after starting,yes it smokes a little
192000 miles
yes its a auxilary fuel pump for WVO,Ive tried to not use WVO system...no change.
all glow plugs have voltage,and all glowplugs glowed bright on workbench,so yes I do assume they are working

how are you testing the plugs on a workbench? are they the original loop plugs, or are they pencil plugs?

yes,I tested on workbench. loop type

There have been two cases on this forum within the last six weeks of loop plugs being wired up incorrectly, resulting in them not working. The squiggly wires and porcelain insulators have to be in exactly the right places the get the current to flow thru the system. Do your squiggly wires get hot and glow red when the key is in the glow position. The glow should be readily visible in the dark, not so much in daylight.