[VirginiaR1500]

I have a 2001 Ram 4X4 with a 5.9 liter engine with 180,000 miles on it. When I try to accelerate (especially with the engine warmed up) the engine misfires and backfires. It feels like it is misfiring at 55 mph but not as bad as during acceleration. I have replaced the ignition coil, crankshaft position sensor, ignition wire, front oxygen sensor and added two treatments of Seafoam in the gas tank. I also replaced all of the plugs, wires and distributor cap and rotor in the fall. The recently replaced ignition wire has a slight electrical glow tat is visible from the outside cover (it is an Accel wire) when I look under he hood at night.
I do not have current error codes since I cleared them about 200 miles ago. Can anyone tell me what I should be looking for?

 

[ramfam]

Check for vacuum leak's

 

[Toms Blue Ram 1500]

The ignition wires sound like their junk . You shouldn't see them glowing at night . Install another set of wires and take a fuel pressure reading

 

[VirginiaR1500]

Runs rough and misses when hot

Thanks for the input. I will check for a vacuum leak (any ideas where I need to focus?) and will replace the plug wires. In case I was not clear, I only recently replaced the ignition coil wire with an Accel wire. Previous to that, I replaced all of the plug wires in September of 2011. Thanks again!