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2008 Tundra 5.7 only 55K miles – What is causing an intermittent misfire at startup? It’s been running great, then 2 weeks ago when I started it up I could feel a small misfire. By the time I backed out of the driveway the check engine light came on. This is what I have learned so far:
  • Only happens when you start the engine and the engine is NOT at operating temperature.
  • The engine code always reports misfire on Cylinder #2 I put in a new plug and swapped coils but it still reports the misfire on cylinder #2.
  • Once it starts to misfire it will continue to misfire until the engine is at operating temperature and you restart the engine. NOTE: You MUST restart the engine for the misfire to go away.
  • One time I started the truck, I felt the misfire and drove it to a parts store to read the code. Engine was fully warm by the time I reached the parts store. I did not power off the engine, plugged in the tester and read the code which was a misfire on cylinder 2. I cleared the code and within 2-3 seconds it logged the misfire on cylinder #2 again. Cleared the code several times and it kept reporting misfire on cylinder 2. You could also feel the misfire happening. Turned engine off, started it right back up, like before no misfire, cleared the code and it no longer reported a misfire.
  • This just started intermittently happening. This morning it happened again, I drove it for about 5 min, engine was about 75% it’s normal operating temperature, powered it off/on, still had the misfire. Once engine temp reached normal temp (about 9 min), I turned off engine, started it back and like before problem was gone.
Any thoughts on what is causing this to happen?
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