Well... this is interesting...

I pulled 2 litres of water through the vacuum tube on the back of the intake.... TONS of steam...

After a few hundred kilometers of driving the truck really started running better... mileage was a bit better... but not much else changed. It started and idles better and is a little snappier on the bottom end.

I ran a container of gum fuel injector cleaner through a half a tank of fuel. Added fuel today after running it through.

Now this morning... the truck ran normal. 6 inches of vacuum in OD at 50 mph.

I got in after work and on my way home I noticed I was able to get 10 to 12 inches of vacuum at 50 mph... a ton less throttle needed to keep the speed.

What the heck would cause such a big change? The weather was exactly the same this morning as after work.