looking for some help with my 6.2 problems

[6.2headache]

I have an ex- military '84 M1009 CUCV, basically a 6.2L diesel blazer with a 24volt system.

The truck starts and idles flawlessly.
I have plenty of power all the way through first gear but after it shifts the truck is just gutless.
I also noticed it surges slightly at light throttle. Like when I do manage to get up to speed and let back on the peddle to maintain that speed.
I replaced the filter.(square block style on the firewall passanger side)
I even tried running it with the fuel cap off just to make sure the vent isnt at fault.

Thanks in advance for any and all assistance.

[6.2headache]

Got this all figured out today, started tracking through the fuel system.
Verified no obstruction to the return line.
At this point I was fairly certain it is the fuel filter in the tank.
So I disconnected the line from the tank to the engine at the rubber connector just in front of the rear passenger tire along the outside frame wall and hit it with some light air pressure.
This has resolved the issue completely, but now I am thinking that i will need to drop the tank, have it cleaned and replace the internal filter.

Hope this helps anyone else this issue comes up for. :)

[john8662]

I was gonna say and air leak somewhere, but yeah, the sock can be plugged. That's like the one thing I won't hardly mess with unless forced.

But very possible.

J