GM-GMC: sipder fuel system 95 4.5 vin w, seat interface, restricted flow

Question
when the injectors are un pluged should the gas spray or  barly seap out when turning the motor over?     befor i tor it apart it would only start if you held the gas pedle down and it only run for a few seconds it has 58psi when key on and 55 whne it dose run . thanks

Answer
You do not have sufficient fuel pressure to check the spray pattern. 60-66 psi is the normal operating range.  If the fuel pressure is less than 415 kPa (60 psi) for Central SFI, it falls into the following 3 areas:

•  A regulated pressure but less than 415 kPa (60 psi) for Central SFI. Amount of fuel to injector OK, but pressure is too low. System will run lean and may set a DTC. Also, hard starting cold and overall poor performance or may not start at all.   

•  A restricted flow causing pressure drop -- Normally, a vehicle with a fuel pressure of less than 300 kPa (44 psi) at idle is undriveable. However, if the pressure drop occurs only while driving, the engine will normally surge then stop running as the pressure begins to drop rapidly. This is most likely caused by a restricted fuel line or plugged filter.

•  A leaking or contaminated pressure regulator valve or seat interface may not allow the regulated pressure to be achieved. Restricting the fuel return line allows fuel pressure to build above regulated pressure, with battery voltage applied to the fuel pump test terminal, pressure should rise above 455 kPa (66 psi) for 4.3L Central SFI, as the valve in the return line is partially closed.

Hope this helps