at wits end . i have 2000 tacoma 4x4 3.4l . when it sits overnight,on the intial start up the engine misfires for 30 to 45 seconds, then smooths out and runs great .occasionally it will set a po 300 code for random misfire but very rarely.all basics are good,  new plugs, wires ,fuel pump and filter.. feels like maybe fuel pressure is bleeding off over night, and air being trapped in fuel rail ,and has to purge air tru injectors,  then it is fine and doesnt skip a beat . is there a check valve somewhere in the system .like in the pressure regulator. or have you came accross this before. random misfires are hard to isolate.ive checked elect conn and are all good. too had timming belt replaced also few months ago any suggestions