hesitation

Hi, hopefully you can help me, i have the vehicle listed above (p10 sri) hesitation at times. now i know that their fuel pump goes after a while, plus this would be one of its faults with hesitation. in which i found little metal particles in the pump filter. also change fuel filter. at the same time by coincidence horse hair was coming out my exhaust. which i found out the muffler is made with this material and in time go bad. my muffler was getting rutting from the inside. now know all this is a fault for hesitation i change them all. trying to get parts is getting very difficult. now i just drove my car the second time since i change the parts and notice i still may have a little hesitation. are there fuel injectors? what should i do? please if possible your knowledge can help me keep Betsy running and being proud.