Starting / Idle Issues: At A Complete Loss-- Any Suggestions?

[gmeline]

2002 Ford Explorer Sport Trac 4.0 SOHC 185k
Problem: doesn't want to start cold unless I turn key to run a few times beforehand. once it kicks-over, it wants to die, rpm's up and down, until finally smoothing out. poor idle. everything else works great.

I've already tried and replaced:
alternator
battery
air filter
Fuel pump and filter
MAF sensor
IAF sensor
EGR valve and vacuum solenoid valve
PCV valve
vapor can vent valve
spark plugs and wires
ran compression test: 200, 180, 180, 180, 180, 180
conducted smoke tests, propane test, starter fluid tests for vacuum leaks
tested fuel pressure: at 65 or above

took to dealer for diagnostic:
they said retrieved CTC P01125 TP sensor intermittent circuit fault and said it had vacuum leak at the upper intake manifold and gasket area and needed new throttle body. I replaced intake manifold gaskets and new throttle body.

NOTHING FIXES IT!!!

any ideas, suggestions, or solutions would be greatly appreciated.
I'm at a loss.

 

[bobditts]

how do all the ground wires and contact points look in the engine bay?

 

[gmeline]

how do all the ground wires and contact points look in the engine bay?

good idea. any particular ground wires that you would recommend inspecting? I'm actually wondering if the cause of the problem might be wiring with the ignition switch in the steering column.

 

[gmeline]

tried new engine coolant temperature sensor as well as replaced thermostat and thermostat housing.
Engine still "flops" when you start it cold.
Give it gas though and after a few seconds, runs fine.

HELP!