I have a 98 S10 Blazer that I replaced the motor in. After putting in a 4.3 out of a 97 Blazer, it won't start. There is no fuel getting to the motor, as I have checked the pressure and there is nothing. The fuel pump will continue to run for approx 15 - 20 seconds after turning the key to the off position instead of the usual 2 - 3 seconds. I was thinking maybe fuel filter but everything on the fuel system worked fine before replacing the engine. Is there something on the new engine that I should be looking at? Maybe a computer issue? What should I check first?