Steve,
Before you replace the fuel pump, you should measure the pressure & also see if the pressure remains after the engine is turned off. To randomly start replacing parts can often cause more problems than you start out with. My 84 had a similiar problem when cold. Seems to me that cleaning the idle solenoid & throttle body along with replacing the hose (it had tiny holes from rubbing) connecting the throttle body to the AMM cured the problem. As for the temp sensor, the one in question doesn't connect to your gauge. This sensor is hooked up to the computer. Signs of failure include a higher than normal idle when the sensor 'opens'. I built my own fuel pressure tester for about $30 using connector/adaptors from a junk yard.