1991 Ford F-150 Truck won't start-inconsistent clicking from

I've asked a series of questions regarding my truck performance and thought I had the problem resolved. The truck seems to be running okay but now has problems starting and the problem is random. With the key on, there is inconsistent clicking sounds from the computer (self testing area). The truck will turn over but not start. If I floor the gas pedal, it will start but will sputter and die immediately and emit smoke from the exhaust. I'm assuming the smoke is from the engine being flooded with fuel. Again, the clicking is inconsistent and quick. I cannot run the code reader during this time. I just checked and can feel that it's the fuel pump relay that is clicking, however, this was replaced about a month ago.