2003 chevy s10 pick-up trans not shifting into 1st gear
 

I have a 2003 chevy s10 2.2l automatic. The transmission has been staying in 2nd or 3rd gear when I come to a stop. if it is in 3rd gear and I manually put it into 1st gear it only goes to 2nd gear. If it is in 2nd gear and hit the gas hard enough, sometimes it will down shift to first when taking off. It will act up about 3 times in a row and then it is fine for a couple of days or even a week. I have replaced all 4 of the shift soleniods, fluid and filter. I took the harness of the trans and computer and put electrical grease on them thinking it was moisture but that lasted five days and it is doing it again. other wise the transmission shifts perfectly when not acting up and there is no computer codes. Any help or suggestions would be greatly appreciated.