I have a 1989 gmc sierra with 5.7. My truck starts ok, but when i put it in gear and start down the road it it acts like it doesn't want to accelerate until i get the rpm's up. I have replaced spark plugs, wires, dist. cap and rotor, fuel filter, fuel pump, and coil. need some help!!

 

hello

 

hmm..just how does it act?..how do you get the rpm's up?...no check engine light?
maybe only 1 injector spraying...or a plugged exhaust