The engine runs very rough in the morning when I first start it and for the first 15 miles or so. It feels like a misfire, but it does not give me any codes of a misfire when tested. When I turn off the engine after 15 miles and start again 5 minutes later, it runs fine the rest of the day. I have replaced spark plugs, boots between the plugs and coils and I still have this problem. It seems to be sporatic but when it does this it is pretty bad. I've also replaced fuel filter, and have run lucas injector cleaner through a couple tanks of fuel. Without a code, I'm stumped. 2 things I thought I may be is a bad injector or maybe an intake manifold leak. If a coil is weak or going bad would it throw a code? and or the same fo a fuel injector?
Sep 12, 2010 at 7:44 PM