Lucky Bells

I took him out for a drive today and as soon as I hit 45 mph the engine started bucking, and it wasn't shifting into 4th gear. At first I was like, oh god the trans is slipping. Which is my worst nightmare because bad transmission would mean I'd have to get rid of my truck....

So, I made it back home and from there I checked the tranny fluid. All was well. I took the truck out for another drive to test it and see if the bucking would start at 45 mph again and, nothing happened. All was normal.  So after some discussion with @Cyclone1066 we've both come to the conclusion that it isn't the transmission going. We think it's a fuel system issue. I've also been noticing over the past week or so the engine has been running abnormally low RPMs, due to not enough fuel getting to the engine. That also explains why it wouldn't shift into 4th gear today. The RPMs weren't high enough.

So the problem? Bad fuel filter, bad fuel injector(s), bad fuel line, or just too much carbon built up into the fuel system is the issue here. Or possibly all of those combined. (I hope not) 

I unfortunately won't be able to get to work on anything either due to this big road trip coming up I gotta get ready for.