i have a 95 blazer ls and recently replaced the fuel pump, exhuast and thet water pump to fix the problem i had (work done may 2010)
the problem: while driving the truck would randomly start to jump like if you were pushing the gas down and up. like you were pumping it. my foot would gently be pressed on the gas and it would do this.

replacing the things above fixed it but this has happend recnetly even after the work was done any suggestions??

 

Have you checked the output from the TPS sensor? It should be ~0.5V at closed throttle and smoothly increase to ~4.5V at wide open throttle.

 

havent checked it no... im not much of a mechanical guy.. how could i do it myself??

thanks a bunch for the help