93 1500 silverado hard rough start idle
 

my '93 350 5.7tbi 2wd is having starting issues when the weather drops less then-10celsius.if i dont run it over night then when i get up in the morning its rough and then if i shut it off for couple hours it will run fine but if it more then a few hours its rough, i have to try like 3 or 4 tries thenm it will start but real roughwanting to stall , but if i rev it up it will run but it wants to stall kinda chugs then it dies i retry and it will but have to give it some gas to keep it runningit runs like that for bout 10 min or less. till it gets warm.:confused::(. block heater doesnt work that is on my to do list, get regular oil changes bout evert 6 months
thermostat or some other valves ???