1993 idle is good while warming up, then dies sometimes at go then dies on road for no apparent reason

Which engine you have?

z28 5.7

z28

Was it doing this before you replaced the parts?

yes

Sounds like you icm might be acting up. Or maybe coil heating up. Are you sure your water pump isn't leaking on your dist? This can also cause similar issue.

My guess would be that the ECM is shutting down the engine because of signals it's getting from a faulty sensor. Perhaps O2? I'm not up to date on all the sensors, but I believe one of them is the problem.

I am not sure about the icm and ecm, is one in the distributer? How much do you think those parts are I have no idea? coil has been replaced also. how do i get the codes without the instrument? Water pump is new.

Advance auto parts has them for $60-$100. They can test yours. But remember that these tend to only act up when they get hot. They may test good cold but actually be bad at operating temp.