80 300CD cranks but no start

[Zackb911]

I have a 1980 300CD/WVO car that I got last week. Its my first diesel and has been running fine on a dual tank WVO setup. Well this morning she didnt want to start. It seemed like a weak battery that progressively got weaker. I did purge back to diesel in the lines before shutting it off last. Jump starting also didnt help at all, still seems somewhat weak but sounds like it should fire. Where can I check? Glow plugs seem fine... Is there anyway to make sure there is no congealed WVO in any lines or injectors? Im mechanical but this is my first diesel!

Thanks,
Zack

[MB-Owner-in-ind]

If the battery seems weak remember that you must be cranking at least 100 rpm to start. Take the battery out and have it checked.

[P.E.Haiges]

Zack,

How did you determine that the GP "seem fine"?

P E H

[Zackb911]

Well I also tried another battey that should be good and I had the same issue. In regards to the glow plugs, I tried checking the resistance on the pins at the junction block on the right(per Haynes manual, I believe I tested the right ones). None of them should infinity but they did range from 0.5ohm-1.5ish... I tried hand priming as well but is there anyway to make sure there isnt congealed wvo anywhereand that diesel is making it through the injectors? Any troublesooting ideas?

Thanks,
Zack

[P.E.Haiges]

Zack,

You might take out the GP with higher resistance and connect them directly to the battery. Use a Vise Grip wrench to hold the GP. The tip will glow bright orange if the GP is OK.

To see if fuel is being pumped to the injectors, loosen the nuts on the injector pipes and see if fuel leaks out when the engine is cranked. Its unlikely that the injectors are plugged because of the high injection pressure.

P E H

[Zackb911]

I checked the GPs again with the voltometer... It seems all 5 are around .6 ohm. The plug has 7 wires total and 2 read differently but they are a different gauge and marking style so I assume they are for something else.

Where is the GP relay fuse? In searching I keep hearing to check it, I dont suppose its the metal strip in the same box if so that looks fine. The light functions as normal (10-15sec) but there is no click or noise when the light shuts off... Anyone else have ideas before I pull the GP's? I hate having to pay for gas to commute in my other car