Help for 2000 Silverado

[tlangl2]

I have a 2000 Silverado V6 with about 50,000 miles on it. About a month or two ago it started hesitating every now and then when I would pull out somewhere and hit the gas hard. Then one day as I was driving to my parents' house about 50 miles away, it would not go over 45 mph. If I tried to accelerate anymore it would sputter a little and go even slower. I changed the fuel filter and it worked fine for a week (save for the occasional hesitating like it was going to kill when I pulled out from a stop) until I drive to my parents' again today and it does the same thing where I can't go over 40-45 mph. I try to show my dad what it's doing about 2 hours later when he gets home and it is running fine again. Anyone know what the heck the problem could be? Thanks in advance.

[kenny-1907]

Could not hurt to try and dump some injector cleaner into the tank as well as some isopropyl. My Silverado was doing something similar to me a while back and the isopropyl solved the problem. After 50,000 miles maybe a tune up would be a good idea as well. Plugs, wires, considering it is a 6 cyl; cap and rotor.