Help, diesel acts like starved for fuel

My problem resides with my 82 300TD. This morning and one night last week while driving 60mph she acted like she was running out of fuel. Both times the fuel gauge was at about 1/8 of a tank or just shy of reserve light coming on.

Last week I got her started off the side of the road. It took several tries and when she started she was not firing on all cylinders. Started out down the road on what felt like 4 cylinders and it took a little while but she cleared out and ran on all 5.

Then this morning the same thing happened on the highway, except that I couldn't get her to fire until I put another 3 gallons or so of fuel in her. Then I still had a heck of a time trying to get her going. After getting back on the road, she bogged down several more times on the way to work. I could keep her going by matting the pedal and as the speed came down to 40 or so, dropped her into "S" and brought the rpm's up, this would eventually clear her out and I would be back up to speed again only to have it happen again.

At lunch today I drove to the nearest station that sells premium diesel fuel, filled her up and drove back to the office with the same thing happening only a little less severe. I was wondering whether I had a bad dose of fuel or not.

Tonight I drove to the NAPA store and back (to pick up fuel filters) and she never hesitated once. But, I also have a full tank now.

I read a post about vacuum in the tank, so at lunch during one of these episodes I stopped and remove the fuel filler cap. Continued down the road and the same starving for fuel scenario happened again.

Any Ideas? Thanks.