Code P0171 seems false

The truck has a hard start condition if left sitting more than a day without starting. Whether cold or warmed to operating temperature. It puffs black smoke and smells rich. When revved up, the black smoke gets thicker and leaves sense carbon stains where the exhaust hits the ground. Sometimes I do have to cycle the fuel pump a couple times to get it to hit. And it will start a couple to four attempts later. MAF has been cleaned, no obvious vacuum leaks (I can normally hear those). I would normally replace the coolant temperature sensor, but this one is supposed to run the gauge and send to the PCM. And the gauge seems right. Suggestions or questions?