My engine won't start :(

[deladrien]

My friend suggested I post here asking for advice.

I own a 1983 Volvo 245GL with a 6-cylinder diesel. The d24t, dare I say?

Owned it a year, got it running a few months ago (5-6?). Ran faithfully until last Thursday, when without warning it simply would not run. Starter would turn it over, but it wouldn't catch. I ran down my battery trying.

Things I've tried since then:
* Replaced the battery. In retrospect this might not even have been necessary, but oh wellz.
* Replaced 5 out of 6 glowplugs (technically, 4 of them were replaced several months ago, but I tested them and they glow fine). The last one, behind the fuel pump, is at least several years old and probably doesn't work, but the car was starting fine on 4 plugs, so I figure 5 is good too.
* Plugged in the block warmer. At first it seemed like it was making heat, but maybe it was my imagination. I've left it plugged in for more than 24 hours since then, and it doesn't appear to be making any heat anymore.
* Replaced the fuel filter, including prefilling it with fuel, since eli said to
* Tested the inline electric pump I installed to prime the mechanical pump. I've left it installed since I didn't really see any reason to remove it, and the car worked perfectly well for several months with it in. It is still pumping fuel to the filter.

I've gone out every day and tried to start it, usually around noon, as I assume it's a little warmer then. The glowplugs appear to light - indeed, i've been double, or even triple-lighting them - and the starter turns the engine reasonably well - I think. Once I got it to catch on a cylinder or two, and it almost seemed like it was going to start, but then it kinda dried up again and went back to just the starter. I had it on the starter for a good minute and a half there, but I was afraid to keep on it anymore cause I didn't want to burn out the starter, and there really didn't seem to be any point after it stopped catching.

There's white or even brown smoke coming out the tailpipe, and the smell of fuel - it certainly seems like there's fuel going into the cylinders.

Eli suggested I get a video of it, which I'll try to do when I can get a volunteer to hold the key.

Until then, any suggestions/ideas?