1991 jimmy 4.3 PROBLEMS stalls/iratic idle

[loco_5_0]

I have had this jimmy for about 1.5 yrs and have never had this problem b4. Started first with the iratic idling.
It was fine for awhile but now i get the truck started, driving along, come to a red light it the rpm's shoot up and it shuts off. I try to start it but it doesn't want to turn over unless I have my foot to the floor. Then once it starts, it has a very rough idle.

any help would be very much appreciated!

[BlazerLT]

Clean the IAC valve and the hole it inserts into with carb cleaner and a toothbrush.

Scrub them good and rinse them out with cleaner.

Reinstall and reset your computer by pulling the negative battery cable off of the battery for 10 minutes.