Ok, so this has stumped myself and the local Super Duty techs at my local Ford Dealer.

Trucks starts cold with a heavy miss and engine surge. After it warms up just a little the only way to restart is petal to the floor and crank for a while.

1999 Super Duty with the 5.4l/ 2 valve.
KOEO active code only. P0505 Idle Air Control Check/Fault. 3 IAC valves were installed including a Motorcraft. Passed a smoke test. Wires have good continuity from the PCM to the valve. These wires were bypass tested also. Just for kicks I changed the plugs and cops also. Also bypassed the CAT. No sensors there to see anyway. The PCM is commanding the valve to go wide open at 80%. Don't know why.

And the strange thing that Nobody can tell me is why my intake heats up faster than the exhaust.

 

Do you have a IR temp gun? Can you get temps of before and after the catalytic converter?

 

Has similar problem in last vehicle. Injectors were partially clogged. Did not show up on scan.

Have them check AF

 

Interesting. But that would cause a lean condition, right? Since the IAC is fully open the PCM thinks it too rich, hence more air to the intake. if this is incorrect could someone let me know. I've been discussing idle algorithms and trim codes with Ford and Chevy techs for nearly 4 months now on this problem. I'm at a loss.

 

The Cat was removed. I feared that it may have been plugged. A new muffler was installed also.

 

After Ford repeatedly told me that my PCM was at fault I decided to take the advice of a Chevy tech and check my intake for a restriction. Once I found out that this truck uses a 98 intake group with the 99 block and heads I resealed the intake. During the repair I found my EGR valve was stuck open. Once everything was back in place the truck started up with no problems. Oh, there was nothing wrong with the intake. Because exhaust gases are flooding the intake because of the bad EGR the IAC valve was wide open to compensate. Why this caused a check fault which is an electrical problem still eludes me. But, oh well. The damn thing is fixed.