Check that the TVS closes at idle. No TVS idle signal, no idle speed control.

PS Don't confuse TVS with the microswitch on the linkage - two different aninmals. The TVS is at the end of the throttle valve shaft. It should have three wires - idle, WOT, and ground. Trace the TVS pigtail to the engine harness connector, and run your contintuity checks there.

Duke