engine miss on 1994 Ford F-150

engine has a slight is not constant. it idles perfect. seems like slight electrical miss while driving. i have changed plugs ,wires,cap and rotor and coil. what else can i do

Asked by for the 1994 Ford F-150
Check the basics again, spray the distributor cap and wires, with a solution of water in a spray bottle, if insulation is good with engine running the engine idle shouldn't change, engine shouldn't misfire if it does you may see sparks finding a path to ground. Some engines are sensitive to EMF generated by plug wires if the plug wires are not routed correctly. Engine running wiggle wiring harnesses in the engine compartment and see if the engine idle changes if so look for the bad connection. Look also for vacuum leaks.