My wife has a 1999 4 door Blazer, 4.3 liter, 4x4 that is getting increasingly hard to start (sometimes it takes 3 long tries to get it going). I was getting a P0442 code (small evap leak) so I inspected the hoses but found nothing. I decided to take it to the Chevy garage for a smoke test. They said that there were no leaks and that all the valves were working properly. They then told me that the vehicle looses fuel pressure with the key on and that it was either the central port injector or the pressure regulator. I let them perform the work but they came back and said that both were fine (After charging me $310). They are now telling me that " the fuel pressure was going up and dropping off and leak down" and that " the CPI unit found it to be the fuel pump. My question is, does this sound like a fuel pump problem? I replaced the fuel pump about a year or a year and a half ago and I remember how pleasant it was. I would hate to go through all that work and $$$ just to find out that the fuel pump is not the problem. Any help would be greatly appreciated. Thanks in advance.
Yes it can be a pump issue. The pump has an internal check valve to prevent backflow. The pump could be faulty. This is easy to diagnose if you have a pressure gauge and shut-off valves for the fuel supply and return lines.