Hello
I think I would like to make a suggestion on how to fix things.
I would have some test equipment and check the operation of relevant parts to a system that is not working properly.
Most likely there is one culprit to your problem. If you replace 10 things to fix it, 9 of them were good!

For your hesitation I woluld hook up to the EHA and monitor the current. I would check voltage on fuel meter plate position pot.
Check throttle switch. Check resitance of coolant temp sensor. ETC.

Other things to check. The fuel meter plate should be in the proper position and move smoothly. When you pull the plug off the ICV the RPM should go up to about 1500. When engine is at operating temp removing eha plug should not afffect idle.

This is a very good forum. If you do tests and post results. I think you will get help.