True, and I am in the different strokes :P

I can remove and replace all my glow plugs.....with out disconnecting or removing anything...

The less I remove, the better....I have really bad arthritis too.....bending over and I get stuck.....legs start twitching and its not to pleasant.....valve adjustments are not very fun for me.....yes, I have been blessed to have a rare forum, that less then 2% of the population has.....makes me feel special :P:P

Regardless of which method is used for removing and servicing glowplugs, I'd like to figure out if the results of my tests/measurements point to a healthy glow system or not.

Money is tight, so I'd rather not replace all the glowplugs if I didn't need to. That money could be spent on a new battery OR perhaps on new injector nozzles if dirty injectors are my problem (too much soot in the chambers?)...

Power the glow plugs with the battery and observe the glow. If it gets yellow red hot at the tip it's good. I use glow plugs till they burn out, that's the time I replace them

Yes I understand. The glow plugs stay hot for quite a while after they are powered and their resistance go up, drawing less current. That's why the first gp you test shows lowest battery voltage and last gp highest battery voltage.

Yes they did show that glowing bright orange color when powered from the battery. Took them about 2-3 seconds to get to that state.

Ah, now I understand what you meant -- good point!

If Money is really tight and you have time to go to the Junk Yard with your Multimeter you can get a handfull of used Glow Plugs for the price of One Glow Plug.

Are mine in need of replacing, in your opinion?

No, since they all glow properly, and the voltage of 10 v across then is within limits. I'd ream glow plug holes, adj valves, make sure fuel and air filters are not restricted, tank is venting properly, and if all that does not help, do a compression test.

You need good compression, fuel and air to start a diesel

I did ream the glowplug holes when I took them out to test. As I posted above, glowplug tips were all soot-covered when I pulled them out, and I reamed out a LOT of carbon cake from those holes.

I guess I'll plan on doing a valve adjustment sometime soon and replace the fuel filters.

Can a compression test be done through glowplug holes? I don't have equipment for compression testing, but what would low compression tell me? Is there anything I could do about it anyway?

A light dry soot on glow plugs is ok, heavy or wet soot is not.

Harbor freight has a kit for compression via glow plug and inj holes. Quality is iffy. If you're lucky you get one that do not leak.

Yea, I'd say light dry soot is what I saw on my glowplugs when I pulled them.

Can injectors contribute to hard starting? Coincidentally my fuel economy has been tanking over the last couple years, along with hard starting below 25F...

Most definitely. Injectors and the IP provide the fuel. The fuel must be atomized by the injectors properly with good spray pattern , matched to each other. Pull the injectors to inspect, rebuild, calibrate them. Injector nozzles should not be caked with wet oily soot. A very light dry soot is ok. Don't forget new heat shield if you pull the injectors.

I did buy heatshields a while back, but I don't believe they are genuine OE... Should aftermarket heatshields be ok, or should I use only OE ones here?

Also, probably if I pull the injectors I should just take them to a diesel shop to have them cleaned and pressure-tested/adjusted... I probably won't gain much just by pulling them, and without proper equipment to check them after cleaning, I fear I will do more harm than good, right?

Yes, take them to a diesel shop and have them popped tested. Ask to observe while they do it if possible.

No problems with after market heat shields afaik. They go in one way. Make sure you get it right and don't leave the old one in there!

Having the Valves adjusted been a big help for People with hard starting as it can effect the compression.
If you do it yourself and don't buy the Special Wrenches; with the exception of the Valve Cover Gasket it is nearly free to do the Valve Adjustment.

Starter cranking speed, Engine Compression, Camshaft Timing, Fuel Injection Pump Timing, Glow Plugs, Block Heater, good Battery (with good cable and ground connections), Fuel Supply System and good Injectors all have an effect on starting.

Also as mentioned Synthetic Oil is a big help in starting in Cold Weather as it allows the Engine to spin faster than with normal Oil.