I've been fixing up this truck for about 3 months now, and I am at a standstill. My fuel pump and tbi fuel injectors aren't switching on when I turn the key. When I tested the plug in for the relay, it showed no control power going to it. How can I tell if this is a computer problem or something else. Is there anything else that wold prevent them from coming on? 1991 Chevy Silverado 305

Zachary Bleam