5.7 vortec running rough

[jpartington]

I have a 2000 2500 GMC Sierra

The reason I am posting here is because it is still the old body style. So it has a 5.7 350 vortec in it. The truck runs rough, it makes the ride very bouncy. When driving it the cel comes on and blinks. When I stop it goes solid. Once I start driving again it starts blinking again. Plug wire, plugs, cap , rotor, coil, and ignition control module have all been replaced. Spider assembly was replaced a couple years ago. I'm at a loss here. Any hep would be greatly appreciated. Only code I can pull from the computer is a random/multiple misfire.

[jpartington]

Any body have any thoughts on this?

[David97]

O2 sensors?

[00Silverado4x4]

I'd have it scanned to see if there are any codes. You said you replace the cap and rotor, are they seated correctly? All plug wires installed on correct plug? No insult intended just asking questions.

[bubba1916]

intake gaskets its sucking water or you need new valve guide seals pull the plugs and see what they look like if their a white color its coolant burn off if its black valve guide seals mine was both but it could be the spider leaking fuel grab a pressure gauge and see what the leak down is upon shut off oh and whens the last time you used any kind of cleaner in the fuel if its still poppet style injection could be dirty too that would also cause a misfire i went with the new style with actual injectors on the end instead of poppets