90 2.8 Trooper shuddering engine

[Burbingus]

Hello!

I have a 1990 V6 Trooper with 235K miles. I was accellerating the other day and the car starting making some loud sounds from the engine. I looked at my engine and my PCV valve was out of the valve cover. I put it back in and the car seemed to run all right for a while, but now it keeps shuddering spontaneously. It has normal power and drive until it starts to shudder when it starts to slow down a lot. I have replaced plugs, wires, air/fuel filter, distributor cap/rotor, pcv valve (good vacuum), added fuel cleaner, checked heads/gaskets. Any ideas? This weekend I'm putting on a new EGR valve and serpentine belt and checking timing. Thanks for the input!

Micah