5000Man

About 6 months ago I noticed when I hit 4100 rpm the power abruptly drops off with occational misfire. Car starts fine, runs fine. Replaced O2 sensor, checked resistance on plug wires, and checked plug gap. Cap & rotor are slightly worn. 155 fuel pump about 5000 miles ago. Original injectors. No audible pinging.

Next planned steps are replacing ignition module, and coil. Any body have other recommendations? Should I continue on the ignition road or should I turn my attention to the fuel system? Could I be hitting valve float?

Thanks