hard starting

i just changed frames on my s-10 light pole accident and my truck has just started to give me troubles starting. I crank it over a couple of times and rump rump rump and then start and other times it will crank as usual for about 4 to 5 seconds any ideas on what might be causing this. it sounds rough as hell when it is cranking to just thought i would throw that in.

Check all the grounds going off the frame

The fuel pump was my cause.Sometimes fire right up and other times 4-5 seconds of cranking.

just changed the fuel pump but did not have to ground wire was coming loose tightened it and fine fine but now the truck is hard to start. so cant be fuel pump

How long ago did you change pump?Ground wire is tight?

changed the fuel pump 1 month ago and every damn ground on that truck is tight and it still sounds rough as f*** i mean sometimes when you first try to start it it will crank for 5 to 6 seconds and then i lay off the starter and try again then it starts but it makes this rump, rump, rump sound half the time and the other time it just cranks. Some people say the hormonic balancer is going out but i dont know that may not have anything to do with it. maybe starter? need help quick it is getting worse now.