So just got the 4.3l tbi all put back together and she runs great. But this morning i went to go start her up to her warm up and she wouldnt stay running. She starts and then about 10 sec later she sputters and dies. I had to sit out there with the throttle about 1/4 for a couple a min and then she stayed running no problems. Any ideas? Is there like an idle screw or cold kick down i could look at? Also its about 15 at night an then warms up to a balmy 25F during the day.