Welcome - it looks like you're doing a thorough job the right way. <img src="/forums/images/graemlins/kewl.gif" alt="" />

The next things I'd do:

1) check/set ignition timing
2) check/replace ignition rotor, cap and wires
3) check the coil
4) check all vacuum lines for leaks
5) check the thermo switch (2 vacuum lines on thermostat housing) - might be broken
6) check all around the intake manifold for leaks (use an unlit propane torch to see if engine rpms increase)
7) check the EGR system if you have it on your engine
8) check the purge system operation
9) check the resistance values of the MAF and temperature sensors.
10)check resistance of the IAC coils
11)check TPS resistance values
12)open the ECU case and look for capacitor leakage

Hopefully you'll find the problem before you get to the end of the list. <img src="/forums/images/graemlins/wink.gif" alt="" />

Frank