Truck developed a slight miss under load when pulling my camp trailer back in August. It has steadily gotten worse to the point that it has no power, and surges / misses when under load.

The truck is a 1994 F250HD 460 manual trans, lifted 4", no cat, 3" exaust from the y pipe back, k&n filter, timing at 12*

After i noticed the miss, I changed the following: plugs, wires, cap & rotor, fuel filter, cleaned the k&n, no change. Self test KOEO codes 111,212, KOER 412, 538

Did a compression test, 1-135, 2-135, 3-130, 4-135, 5-138, 6-140, 7-135, 8-140. Tested all sensors for efi, within specs. Tested fuel pressure, checks out, checked all vac lines.

Replaced TPS, slight improvement, cleaned IAC, no change, changed coolant temp and air temp sensors with no change, replaced ignition module, no change, replaced coil with a slight improvement, swapped a map sensor, no change. Pulled the pcm to check for leaking capacitors, looks fine.

I am running out of ideas. The truck idles fine, hit the throttle quick and it stumbles for a second and then recovers. When driving, it is fine with no miss when the truck is cold, when it warms up it starts to miss. Drives fine starting in 2nd, falls on its face in 3rd and 4th under load, is fine at wot. The problem occurs on either fuel tank.

In the last week, the neutral start switch on the clutch rod has been acting up, does this switch have any effect on the timing or fuel system? Maybe a bad dizzy? Any help would be greatly appreciated.