2004 Chevy Express 6.0L

[Jerryo]

Have a 2004 Express 6.0L. After idling for two or three minutes eng. starts to miss. # 6 cyl. developes dead miss and other cyl on same bank miss intermittently. Start driving and it will not stop missing. You can stop, kill engine, restart and miss is gone. Drive and it runs perfect at all speeds until you stop and idle. Then same thing happens again as described earlier. Does anyone have any suggestions? Fuel press. good, no smoke, has had recent tune up and only trouble code is PO300B.
(engine misfire detected)

[MT-2500]

Originally Posted by Jerryo

Have a 2004 Express 6.0L. After idling for two or three minutes eng. starts to miss. # 6 cyl. developes dead miss and other cyl on same bank miss intermittently. Start driving and it will not stop missing. You can stop, kill engine, restart and miss is gone. Drive and it runs perfect at all speeds until you stop and idle. Then same thing happens again as described earlier. Does anyone have any suggestions? Fuel press. good, no smoke, has had recent tune up and only trouble code is PO300B.
(engine misfire detected)

I would check camshaft retard setting.
If over - or + 3 degrees reset it.

Got good spark to that cylinder.
Check and Swap plus and coil/wires and see if miss moves.