I have looked and looked and was hoping you guys could help me. About 4 months ago my Blazer died. Acted like a fuel problem. Checked the fuel pressure @ test port and it was about 40 PSI. Did the easy thing and changed the fuel filter and the pressure jumped up to over 50 and all seemed OK. The past month it has been harder and harder to start then it started knocking off randomly. Rechecked the fuel pressure when it wouldn't start and it was around 40. When it would start it was around 55. I did the next easiest thingand changed the FPR in the plenum and now the pressure is about 50 (key turned on). However, it will not start at all. What should the pressure be? Or do I need to change the fuel pump?

More data, wouldn't start ... squirted in some starter fluid and away it went. When running fuel pressure was 54 psi. After I turned it off it settled at 56 and did not decrease for until I bled it off 10 minutes later. So my question ... Is this fuel pressure low enough to cause it not to start?

 

I just tested mine at 59psi sounds to me your low, can hear the fuel pump run when you turn on the key.