2001 chevy blazer 4.3. about a week ago i got in my truck to go to the store i started it drove off. it drove fine for a few min. but than got super choppy. like a bad misfire, or maybe lack of fuel. so i left and it was still driveing that way got home shut it off turned it back on and it was fine. i thought it may be the fuel but place i got it from just from replaced the fuel pump and filter. i have gas in the truck. when i replaced the plugs 2 days ago it got a little better. i dont knoe if this has a difference or not but i changed the auto tensinor because i was seeing it go way up and down . replaceng it fixed that . before repair i was also haveing some voltage problems were voltage was droping low and was reading low before start. still drops low some times before start .... could that be the alt going out or is that part of the problem. also the day i did the spark pulgs i drove 5 mins to store on the way at the light all gauges droped to nothing twice in a row for a few secs chokeing engine almost out. spark plugs were a little burnt on driverside. pass. side lokked pretty normal ..... could it be rotor and cap have not pulled but look brand new. maybe coil ... please help

 

can anyone help

 

Have the rotor button an cap been replaced? Take the cap off and look and see if the points look worn.