My 98 GP GT shudders when accelerating ~1/2 throttle or more off the line. The shudder seems too "solid" to be a miss, even though the plugs are getting old. I have experienced a little hard shifting 3rd -> 4th when warm & after going around a corner, which mostly went away after overfilling tranny slightly. Otherwise the car runs great. Transmission solenoid? CV joints? Ignition? Thanks.
