My 2011 Patriot that we bought new has developed an issue of overloading cylinder #1 with too much fuel, which fouls the spark plug, and makes it obviously start missing. We drove it Tuesday with no issues, but yesterday the wife went to go and it was hard to start. After it did start, it ran rough and the check engine light came on. I scanned the codes and found P0301, cyl.1 misfire. No other codes were present. I pulled the plug and it was fuel fouled and whitish smoke came out of the tailpipe. I cleaned the plug but it still missed, so I checked the coil on plug and it works well. I swapped coils with another cylinder but the problem is still on cyl.1. I suspected a bad injector, so I swapped the injector with another cylinder, but cyl.1 still loads up with fuel and smokes out of the back.
I checked compression and its about 150 psi. When I removed the gauge it was packed with fuel. If I run it with no spark plug, it blows fuel out the cyl. If I unplug the injector on cyl1 it will smooth out for a few seconds with the plug installed then starts missing again due to obvious lack of fuel. As long as their is no fuel, the smokes stops out of the rear. It is not black smoke. I haven't driven it in its present condition so as not to destroy the Cat converter. I cannot understand how only one cylinder gets too much fuel. This car has only 68xxx mi., and other than having a throttle position sensor replaced, there have been no other parts replaced except routine maintenance items, (belts, hoses, oil changes, filters, brakes). I am finding no other examples of the online and hate to take it to a shop if there might be a fix that I am overlooking. I have suspected a possible defective fuel pressure regulator but haven't found where it might be located.
I checked compression and its about 150 psi. When I removed the gauge it was packed with fuel. If I run it with no spark plug, it blows fuel out the cyl. If I unplug the injector on cyl1 it will smooth out for a few seconds with the plug installed then starts missing again due to obvious lack of fuel. As long as their is no fuel, the smokes stops out of the rear. It is not black smoke. I haven't driven it in its present condition so as not to destroy the Cat converter. I cannot understand how only one cylinder gets too much fuel. This car has only 68xxx mi., and other than having a throttle position sensor replaced, there have been no other parts replaced except routine maintenance items, (belts, hoses, oil changes, filters, brakes). I am finding no other examples of the online and hate to take it to a shop if there might be a fix that I am overlooking. I have suspected a possible defective fuel pressure regulator but haven't found where it might be located.
