Toyota Repair: toyota tercel sluggish, spark plug wires, toyota tercel

Question
I have a 93 toyota tercel with a manual transmission. 241,500 miles on it!Yikes! Up to this point it had been running fine, but recently it has started to stall out when in neutral/idling unless I keep slight pressure on the gas pedal. Now it is struggling with accelerating. I have to keep it in a lower gear then I have ever had to before and going up hills is nearly impossible. My brother told me to check the fuel filter, but I have no idea where it is. Any suggestions? Oh and it's making a loud puttering noise all the time. Thanks ahead of time!

Answer
It sounds like there is an engine misfire, remove the spark plugs and check them, if you have access to a compression gauge, check the compression on each cylinder, if it is good(150-175psi) you can rule out any valve or piston problem and it is probably related to the ignition system(spark plug wires, cap or rotor or a cracked ignition coil,