I have a 1995 blazer 4.3 v6 with CPI injection. Last week it quit running so I replaced the fuel pump, and fuel filter. Still did not start so I replaced the spider injector. The truck ran for 4 days then quit again. I checked the fuel pressure and found the new pump was not providing enough pressure, so I replaced it with a better pump. I rechecked the pressure and it was at 58psi, truck still would not start. I pulled the plenum and pulled the fuel lines from the injector and turned the truck on, I have fuel to the injector, but not out so I replaced the injector, still no fuel coming out of the injector and truck will not start. If I use starting fluid or pour gas directly into it it will start and run until it burns off what I put in, so I have good spark and good fuel pressure but I am not getting fuel through the injector to the cylinders. What is my next step to fix this.