weird starting problems glowplugs/injector 1983 300sd

[1977busman]

So recently it has been getting much cooler here at night. And if it id below 55 my car does not like to start very easily. It will fire up just like always then shutter back down to a halt. If I tap the accelerator while its just fireing, it stays and eventually evens out.
Background info:

• bought car in august and never had any problems
• Car now has 212,500 miles on it
• my number 5 injector is "damp" but not dripping or anything
• Car will start fine once initially started for the day.
• I can start in with or without the glow plugs, it just turns over a few more times without
• I know I am getting at least a few glow plugs working, because it starts noticeably different with or without them.
• If I plug the car in it does start a little better, but still shutters a little.

I did attempt to test glow plugs, and here is what I did:

1. got into the relay and tested ohms on each hole on the connectors going to glow plugs-I got .9 ohms for each one.
2. Then I checked the strip fuse and it was fine.
3. Tested battery and im getting 12.98v when NOT running.
4. Then tested each glow plug, and this is where I think I messed up. I held the negative to the nut of the plug, and the positive to the end, and got .9ohms on each one. Was I supposed to remove the wire to the glow plug? and was I supposed to remove the whole glow plug itself?

So should I be looking for glow plug problems, or fuel problems? and Please tell me if my procedure was correct with the testing.


Oh and ill be back later with transmission problems...