I have a chevy silverado - 5.7 engine. It runs rough, wont idle and most time dies unless i pop it in neutral, shakes and sputters when i accelerate and not much power. I have replaced the air filter, gas filter, ERG valve, ERG relay, spark plugs, wires, rotor, cap, PCV valve and hose going from PCV to intake and vacuum hoses on intake. I have tested the throttle position sensor and idle air control valve and appear good according to the service manual. Any other ideas?

Fuel Pressure/Pump?
Injectors?
Fuel Pressure Regulator?
Are there any codes/check engine light?
Ignition coil?
Just off the top of my head.

Remove the air cleaner and look into the throttle body and see if there is gas coming out both injectors.If only one is working then switch the wire connector from one injector to the other.This will tell you if the injector is bad or if it is not getting a signal.Check for good vacuum at a good vacuum port.Should be close to 20 inches of vac.If not then this could be a good sign of bad timing or plugged converter.Hope this helps.Good luck.

Not sure if this is an old post and you have already solved your problem,but,i have a g10 chevy van and it started running the same as you have explained.took it to mechanic after spending time on it myself,changing different sensors ,etc,after he gave up,i mentioned ecm (the main brain),he said no that's not the problem,it did,t show anything on his scanner,i figured for ***** and giggles i,d change it,bought a new one didn't clamp it down,in case it didn't help ,i could take it back,so,i just plugged it in ,started my van ,and it ran beautiful.....but i would check your injectors like the other lad mentioned.....good luck