I have an 88 pick up that is giving me fits. It wants to die at idle when cold and will stutter and buck when driving at a constant rpm...even when warm. It accelerates and decellerates fine but can't cruise without giving me whiplash. I replaced the cap and rotor which were quite worn and it made things a little better but problem persists. It is a manual trans. I disconnected the O2 sensor and the truck ran the same..no better no worse...possible culprit?Hoping to get some good advice here.