Question Asked: Intermittent misfire.Stumble on acceleration,Dies,Various codes,No service light
August 03, 2013, 07:52 PM
Vehicle misfires sometimes,Occasionally dies Tach and speedo go dead will not restart until the key is cycled fully off then back on Odometer reads only lines until restart then quit working all together,Intermittent Heavy Stumble on acceleration not a misfire more of complete loss of power momentarily then comes back on. Set various codes for All the above sensors one at a time without check engine light. Has freeze frame data sometimes. Code and data clear on first key cycle. Crank,TPS,Knock,cam,and MAF sensors all test good. Battery 12.6 volts key on,14.2 volts running,Replaced coils and secondary O2 sensors, EVAP monitor will not set. Never the same code twice. All symptoms clear up for a day or two then come back one at a time never at the same time. Checked grounds and commons for voltage and resistance. I suspect PCM ground or PCM power feed. Possibly on the VSS circuit. Any help would be appreciated. Thank you.