What no buss means is that the cluster is not able to communicate with pcm. What is probably happening is that a 5 or 8 volt sensor has a intermittant short and the pcm is shutting down to protect the circuit. If you had a scan tool I bet that everytime it restarts the starts since clear is 0 key starts due to pcm reseting. Crank sensor is most common for this but again it could be any 5 or 8 volt sensor. Have also put in a few 02 sensors for this issue.