2007 Challenger 180-215 - Engine missing after warm up

[Abrisebois]

When my engine warms up after a couple minutes of running, the engine in my Challenger start running real rough. I won't get past 4000RPM and the engine will shake quite a lot. Pulling the throttle back to 2500RPM, the engine runs rough but every so often smooths out intermittently, less as the engine warms up more. I replaced the plugs and the was no change.

The only thing I did was changed the oil with Rotella T4 JASO MA certified oil and cleaned out the bilge area. I went over all of the sensor connector plugs and put dielectric grease on them.

When I unplug the fuel injector or ignition coil on cylinder #1, there is no change. Doing the same on cylinders 2&3, the engine studded significantly more.

Any suggestions on where to start?

[jpt7779]

Install new spark plugs as they foul out very easy.

[Shark]

If you changed the plugs as stated above, then next thing is to check your Inter cooler for leaks.

[spinyard]

why do the plugs foul? I noticed that if i let the boat sit for a long time at least one of the plugs goes bad, is it the bad fuel?