cold start trouble is here.
 

All glow plugs test good. Voltage to gp's when ignition in glow plug position. New alternator. Cleaned battery terminals. Cleaned terminals that are on the body under the air intake. Battery tests good at local auto store. Cleaned the ground wire. Valve adjust 5000mi ago. Replaced primary fuel filter.
Im at a loss for what to do next. Any ideas.

I read in another thread that you shouldn't press the gas until after the engine has started firing. Maybe that'll help?

Ive tried various throttle stuff. Mostly no throttle at all as I understand that it just dumps cold fuel in the cylinder. Some say about 1/3rd throttle such that the slack is just coming out of the linkage.
My hard start probs are at pretty moderate temps though and accellerator pedal position hasnt been a finicky thing in the past. 35F lows at night and 50+F ambient when I try to start it.

Check the injection pump timing. A very few degrees can make a real difference on cold starting.
Not too noticable on other things if a little off. Some diesels even have an advance mechanisim for cold starting. Remember as the chain ages the tendency is for the pump to retard in timing. That is the worse direction where cold starts are concerned.
Should be checked especially if never done in last 50k or so. Basically just good housekeeping as well.

Cold in Chattanooga??? Damn good thing you dont live in the Midwest!

Have you plugged your car in at night? Have you double glowed? Triple even?

Are you holding on to the ignition until it runs or are you letting go while it is still stumbling?

How did you test the glow plugs? What resistance did you get?


Signed,

And Ex Wisconsinite that had a bunch of diesels and start them at -10F without plugging them in.

I went and rechecked my ohm readings ala NCBenz - and....
Dee dee dee. I was getting readings in tolerance becuase I had unplugged the wrong harness.
AKA this was NOT the harness that I was unplugging. I was unplugging a different one.
Measuring correctly now there is only one plug that has any resistance. All the rest are infinate resistance and are 100% shot. No wonder it wasnt starting.
Parts store is bicycling distance so I should be able to get new GP's in there shortly.
Electrical is probably not everything it should be though. I got 12.3v across the battery terminals, 11.80 while plugging, and 10 ish while cranking.
Plugs stay on for about 17 sec when igniting switch turned on.

Are you talking about the light or the actual voltage at the GPs (not the same). The light is controlled by temperature and tells you when to start the engine. The actual GPs should stay on for about 35-40 seconds.

I noticed mine has a block heater on it. What guidelines are there for using those? It doesn't get THAT cold in the DC area most of the time. At what temperatures would you consider using the block heater?

I usually don't bother with the block heater unless it's below about 15-20F. A couple of hours of heating is adequate, but I usually just leave it plugged in overnight if it's going to get that cold.

I used the "listen for the relay to click" method and confirmed with a voltmeter.
Only autolite available at the nearby f.l.a.p.s (Advance, Autozone and orileys)
To get bosch may take ordering from napa.
The plugs I had in there are Bosch 0250 201 039. The flaps websites that refrence bosch have a part number 80006. Are they the same thing?
84 300sd

The criteria I use to determine wheather to use the block heater on the truck is not so much the outside temperature as how fast I will need power from the engine. If I'm going up the street in no hurry, I can loaf it along and let it just warm up that way. If I'm going to work and I need merging power on the Interstate just a scant 4 minutes out of the driveway, I'll plug it in.

I have the cord on a timer that comes on about 4AM and runs until I leave at 7AM. That's usually enough to have heat coming out of the ducts by the time I reach the highway when the ambient is below 40F.

I plug in when it gets near freezing. My car starts easily (usually 2-4 cranks after glowing a few seconds till the light goes out), but I would rather plug it in every night than replace the starter from extra cranking that a dead cold engine requires. I also use a timer that turns on about 3 hours before I leave. I don't think the PO ever plugged it in.