1992 Chevy S10 2.5L-4 cylinder. just started today outta no were. it idles really rough and pops then when i step on the gas it sputters and pops also smokes a little. help please..

in need of tune up--fuel pump--fuel filter --bad coil pack -egr valve carboned up -cat converter clogging --throttle body needs cleaning

check your plugs and coil if you have fire check fuel pump to see if your getting the right amount of gas do you have a check engine light code

With petrol engines it is usually best to start at the spark plugs , being in my sixties and the old school , I use the old methods . Spark plugs indicate a lot , they are the business end of what makes it all work . If they are very fouled up black and oily , it usually indicates bad mixture of fuel and air , if they are oily black it may mean heavy cylinder wear etc spark plug manufactuurers are usually happy to supply a diagram with all the indicators on it .

dry gas /probably have water in the gas and it accumulated when you jacked it to change oil

Could be a vacuum leak as it falls off under acceleration and does not play a part then. Check for broken or cracked hoses.....

Sounds like it could be a mis-fire. At an idle, remove a plug wire to see if it stalls. If it does, re-install it and go to the next one. If you remove one and get no change, that cylinder is the problem. Test for spark.

scan check egr valve make sure its working. check plug wires and vacuum hoses +pvc valve make sure its not stuck open.bad or dirty fuel injections.causes rough idling.if all is good do a compression test to check for weak cylinders or low compression.

adjust your carb, the 2 screws on each side of the carb adjust so you can get the car to idle correctly, also check your distributor

Make sure all the glow plugs are working.

you could put the pickup on a cylinder pressure test and see if you have a bad valve causing the engine to pop.
you could have a bad wire or spark plug.
the timming chain could of went off a cog on the timming sprokets causing to pop.
gettin to much gas could cause it to.