1991 Jeep Wrangler, loosing spark

1991 wrangler 2.5 Manual Trans.100,000 miles, The engine has a misfire while reving up in the driveway then holding at a steady rpm, no rpm also, steady misfire, The engine will backfire out the tailpipe and runs very rough, on driving the vehicle, taking off from a stop, the vehicle will jerk constantly under a steady rpm, press on the throttle and the jerking goes away until a steady rpm is met again, happens in any gear, distributor rotor movement is there, but minimal. compression 165 all cylinders, replaced with name brand products: ignition coil, wires, cap, rotor, champion plugs, fuel filter, Motorvac intake and injectors, salvage yard ECM (same problem), crank and distributor sensor, fuel pressure, 40 psi running idle, pull vac. hose 48 psi engine idle. ignition coil= 39kv, at plugs with misfire 4.9kv, timing light will stop flashing. no spark line on secondary waveform, primary side goes directly into the firing event, no module timing control, timing advance is 12-14 idle and 36-38 cruising at 55. , I have seen alot of posts about this style of problem, but no fixes, Has anyone seen this problem fixed that has not posted the fix? Steve Ayers