Engine Performance problem
2002 Chevy Avalanche V8 Two Wheel Drive Automatic 150000 miles
When accelerated truck goes really slow till around 30mph then it accelerates properly. I have to step on gas pedal at around half way so that acceleration can improve, otherwise when stepped all way down it slows down (losing power). It also randomly has its moments where I lightly touch the gas pedal and it over accelerates with a nasty pull when changing gears (rare).
I have used fuel injector treatment and changed the fuel pump, but problem persists.
Hopefuly you changed the fuel filter when you changed the pump. Ifnot change it and check the fuel pressure. Check your vacuum and if it's around 15" at ilde have your converter checked for partial or being clogged. Also clean your throttle plate on both sides with choke cleaner. If your fuel pressure is low have your regulator checked for proper operation.