Here are the specs: '90 Chevrolet Suburban 5.7L TBI TH400 241C. There is no detectable pattern as to when it won't start. When it acts up, I can hear the fuel pump pumping yet there is no fuel from the injectors. I was told of a way to check injector pulse with a digital multi meter, which I did. This tests to see if the DC voltage at the injector plug changes while cranking the starter. The voltage did change, indicating pulse. Although this will not tell if the pulse is proper. Thinking it was possibly a fuel pressure issue (ie pressure bleeding off through the fuel pump) I replaced the fuel pump (new AC Delco pump). This did not change the symptoms. Any ideas? Oh ya, once it starts, it runs great!