Questions:
Carl in Florida - - - - - - - - - - We need an HO Amtrak SDP40F and GE U36B oh wait- We GOT THEM!
Are you running an analog engine on address 00 at the same time? That will slow down the system response time.
What brand and type of decoder do you have? What scale? Your symptoms sound like a possibly bad decoder, especially if it's an MRC.