4.3MPI sputtering at 3500 RPMs why??????

[myentourage]

My 2009 4.3 MPI just started sputtering at 3500 RPMs. I changed the fuel filter and checked the pressure and everything is ok. I tried swapping out the coil, the map sensor, and the crank sensorwith the sister engine and still no luck. It is not giving an alarm so im not sure even if the scan tool will pick it up. I recently had a valve go bad and ingested water in the cylinders so i replaced it with a brand new long block from mercury. But i am still getting this cutting out at 3500. Any suggestions on where to go???

 

[Levinz11]

Re: 4.3MPI sputtering at 3500 RPMs why??????

My 2009 4.3 MPI just started sputtering at 3500 RPMs. I changed the fuel filter and checked the pressure and everything is ok. I tried swapping out the coil, the map sensor, and the crank sensorwith the sister engine and still no luck. It is not giving an alarm so im not sure even if the scan tool will pick it up. I recently had a valve go bad and ingested water in the cylinders so i replaced it with a brand new long block from mercury. But i am still getting this cutting out at 3500. Any suggestions on where to go???

How recently??