You are sure putting a twist in this. I thought you said you took the wire on and off and it ran different. By chance did you check the sensor after it is hot for the 350 ohms?

My guess is that you are getting better at troubleshooting the harness!

Now that you are so good at tracing to the ECU. I would make sure that the throttle switch is for sure sending a signal to the ECU.

There needs to be a signal to ground pin. Either closed or open just as the throttle is cracked opened.

This tells the ECU what you want it to do and when.

Just thinking of what to rule in!

The plugs, wires cap and especially the rotor button are good. Right? Vacuum tee's and lines. I threw this in cause you have to reach right pass these to get to that connector.

If these check out as working every time I would "lean" towards an overheated Air Mass Meter or a air leak between the AMM, the throttle or intake.

I'm still leaning here?

Inspect the bellows tube carefully. Especially the port where the flame trap connects on. Both these hoses and intake side of the flame trap have to be good and tight.

In fact I would pull the bellows and the AMM. Look inside it with a bright light and look for the really fine wire stretched though loops in the center and make sure its intact.

Flex the bellows and I like using a compact fluorescent light inside it. Holes or cracks in the convolutions.

There is a lean condition being presented from what you have said. Excess air getting in that you got to locate or the AMM isn't reading air coming through it correctly.

I hate to pick on the electronics but the AMM are more prone than the ECU. This is due to failures caused by heat from the air cleaner thermostats failures or dirt and oil smut vapors.

Bosch knows there can be a problem with this or they would have not built in to the ECU program a 1 or 2 second burn off of the heater wire in the AMM. Every time the ECU records a rev over 3000 rpm it is programed to burn the wire to clean off impurities. It does this burn after the key is turn off. Its pretty hard to drive the car and not go over the 3000 rpm. So it is possible that it has burned it own wire?

This is as far as I can think this unless you come across something more twisted. Keep us posted!