Hi everyone i have a 97 chevy blazer zr2 about 2 months ago i had a fuel leak and replaced the tank and installed a new tank unit with it. I just recently had it stop running and will run if gas is poured in the intake so i assumed the pump was bad so i swapped my old pump in which worked fine when removed and after installing it still will not run. Is there something else that might be making it not run. Any help would be very much appreciated thanks.

 

Is the fuel pump grounded properly? I would check the continuity between the ground pin on the connector, and a clean chassis ground to be sure. The next thing I would check is the depth of the fuel tank. If the new tank is too shallow, the pump will struggle to get fuel and will overheat. Did you replace the filter with the tank and pump?

 

Check simple things first, though. Sorry about that. Check and make sure the fuse isn't blown for the pump and then check and make sure the relay is kicking, if those check out good, check the rest of the system.

 

fuses are all good and the pump is coming on and priming up just wont start. i replaced the filter when i put the new tank in and put a new one on today just to be sure but still nothing. How does the spider injection work? Could this be where my problem is?

 

Have you done a fuel pressure/ leak down test? This will help diagnosing the issue

 

The spider injection works with 6 injectors centrally located in the plenum. There are 6 hard plastic lines that run to their respective cylinder ports with poppets that open when enough fuel pressure is applied from the injectors. There are 2 metal lines going into the back of the injector assembly. The larger line is the feed from the fuel pump and the smaller is the regulated return line to the tank. The fuel pressur regulator (the silver cylinder on the back of the injector assembly) uses plenum vacum to regulate the amount of fuel allowed to bypass the injectors. The greater the vacuum (throttle plate closed) the more the regulator opens and allows fuel to bypass the injectors and flow back to the tank. The lower the vacuum, the less the regulator allows fuel to bypass, thus increasing fuel pressure to the injectors. As 4x4gs10 stated, you have to do a pressure and leakdown test at the service port located directly to the left of the distributor. Take a standard fuel pressure guage capable of reading over 70 psi and thread to the service port and prime the fuel pump. With the pump priming, you should read between 58 and 65 psi IIRC. There are veteran members of the forum who can either verify or correct these numbers. The lines should maintain pressure above 55 psi for 10 minutes. If it does not maintain pressure, there is a leak, usually internally, somewhere in the system. If it does not reach 58ish psi, then there is a problem with either the pump or the regulator.

 

the above picture is off a vortec 5.7L v8, but is the exact same design as the 6 cylinder, obviously with 2 less cylinders.