fueling issue possibly

[ricnor]

My 1997 454 K2500 4x4 auto has been running a bit rough after a long standing period. Took the plugs out and the offside bank of plugs (drivers side) are sooted up (blackbut the nearside bank look fine.
I cleaned them all up and swapped them over from one side to the other, started the motor and had it running for about three to four minutes, including revving it up to about 3000rpm. I let it all idle for about a minute, switched off and removed the plugs, again the drivers side 4 plugs are sooted up more than the other side.
By swapping from one side to the other I have obviously eliminated a bad batch of plugs.
Any ideas what would cause all four plugs on one side to become more sooted up than the other side?
When idling the engine was fairly smooth.

[j cAT]

Originally Posted by ricnor

My 1997 454 K2500 4x4 auto has been running a bit rough after a long standing period. Took the plugs out and the offside bank of plugs (drivers side) are sooted up (blackbut the nearside bank look fine.
I cleaned them all up and swapped them over from one side to the other, started the motor and had it running for about three to four minutes, including revving it up to about 3000rpm. I let it all idle for about a minute, switched off and removed the plugs, again the drivers side 4 plugs are sooted up more than the other side.
By swapping from one side to the other I have obviously eliminated a bad batch of plugs.
Any ideas what would cause all four plugs on one side to become more soot-ed up than the other side?
When idling the engine was fairly smooth.

fuel pressure regulator leak ? check that the fuel pressure holds on engine shut down