I have a 92 Nissan Pathfinder that is sputtering a lot, almost like it's going to stall out when I am going up hill or even when I just start to get going in 1st gear. Even when I floor it, if the engine is giving too much of a load it seems to wanna almost die out on me. There's a little smoke that comes out too when it acts up.

It seems better once the truck is warmed up.

I replaced sparkplugs to see if that helped and it didn't really help at all. Also the wires tested out fine, and distrubuter cap seems fine as well. I have cleaned out the throttle body too.

There's also a slight knot that you can barely hear at 3000+ rpms.

Any ideas? I'm assuming one of my pistons (Or a few of my pistons) rings are bad.

Try cleaning your mass airflow sensor, check the air filter, run the ECU error codes and see if anything is stored, change the fuel filter, the list goes on.