BuildCraft version: 7.99.8.2
Forge version: forge-1.11.2-13.20.1.2588
Link to crash report or log: NOT Crashing
Singleplayer or multiplayer: SP
Steps to reproduce: Filling a hole 616161
Additional information:

It loads in spurts. sometimes not at all. Sometimes it loads fast, other times it loads really really slow.
Don't matter if I power it with a combustion engine or a kenetic pipe, even if I power it with power from IC2 (industrial craft 2), it does the exact same thing, the lagging is in and out. If it freezes up I can toggle between "invert" and "do not invert" and get it to work others it take backing completely out of the game and relaunching.

I thought the BetterFPs mod was causing it so I took it out... No change.

IDK, I am ready to go back to 1.7.10 where things were stable. The only one complaint I have about MC is the fact they are constantly updating and I know it's a chor for we developers to keep mods up to date.

This is the only thing I have lagging in my forge 1.11.2 world.

is this FPS or TPS lag? in case of fps can you look in the F3 pie chart at what is using most of it?
in case of TPS can you /debug start, give it a minute and let it lag, then run /debug stop and upload the profiling output it generates?

an nps profiling file could also be usefull if you know how to profile java apps

The filler is buggy in 1.11.2 and 1.12.2 at the moment. In 1.12.2 it's not even available in survival (partially) due to this. See #3993 for status. (Note that 1.11.2 is no longer receiving content updates, so I probably just forgot to disable the filler in the 1.11.2 versions)