Ford Disaster

Well I'm working on a F-150XL 5.0 Automatic and need your assistance. Runs better but still stumbles at idle and when driving at steady speed below 50MPH or slowly pressing the accelerator it starts to shutter, as if losing ignition or (off & on) but if I give it the gas it smoothes out and accelerates fine. Check timing and it's dead on 10 degrees BTDC as label calls for but after putting the stunt back in and restarting it seems to retard timing and idle will shutter until it advances back up and it will do that in cycles. Still holding the following TDCs:

Code 411-Cannot control rpm during KOER low rpm check

Code 565-Canister purge circuit failure

Blocked off vacuum to the purge valve and no change but the purge valve is opening at idle. Purge valve circuit getting proper voltage. Checked grounds under hood and they are intact and showing a good reading. Where else would you go? So far this is what has been changed:

TPS

IAC

Stator Assembly

Ignition Module (remote mounted on driver's side fender)

Plugs

Wires

Distributor Cap


Please help me get this thing out of my yard!!

Any ideas out there in Ford never land??