1993 Eagle Talon 1993 Eagle Talon Giving EngineCoolantTempe

1993 Eagle Talon DL with 1.8 Liter 4 Cylinder 5-Speed Manual is giving engine coolant temperature sensor code and not cranking when cold (code 21). I have replaced the sensor 2 different times in the last 2 weeks with brand new sensors. The thermostat is new and the coolant is new and filled to the proper level. When I replaced the sensor the 1st time with an Autozone brand, it crank right up immediately and continued to crank fine for about 5 days with no engine codes displayed. After 5 days, it started not cranking again when cold and gave the same "engine coolant temperature sensor" code. I decided to get a BWD sensor after a couple of days, thinking it might be a better part. When I installed the 2nd new sensor, the car wouldn't crank when cold at all. I have also replaced the mass air flow meter with a known working one, on this model it has the air temperature sensor built into the mass air flow meter. I even wondered if the oxygen sensor could play a role but everything I have read says, no, because it doesn't have much if anything to do with cold starts. I have racked my brain with this, I'm a car dealer here in GA and am simply trying to sell the car but I want it right for my potential buyer. It pops off some when it finally does crank when you give it gas, almost a flooding sound from gas. When it finally cranks, if you leave the gas pedal alone, it will run for about 4 or 5 minutes and get warmed up fully and it runs and engine revs perfectly. Just a cold start issue, please Help!