1993, idles bad

I bought a 1993 olds achieva s 2.3l vin3.
The service engine light, and the check gauges light were on.
I found a sensor on the tranny not plugged in, plugged it in and the check gauges light turned off, then i checked the codes and got a code 35, that was the only one i got. so i cleaned the throttle body and iac valve, started it ran fine no Service Engine Light or check gaues lights for about 5 min. then started idling bad again. and the Service engine light came back on... the rpms will bounce back and forth between 1600 and 1850 rpms, and drops to 1000 when i turn on the a/c. i did take the iac valve out and turned the key and it moves. any help would be appreciated. btw i did change the coolant pressure cap, it overheated and was coming out of there, and i changed the spark plugs and boots.

Methinks what you bought is the other person's problems....

Know why you found the harness to the tranny disconnected? That's an old trick to prevent the the TCC from locking up the tranny, which causes a stall when coming to a stop....car will restart right away, and then dies as soon as you put it in gear.....

You definitely have an idle problem if it is at 1800rpms....code sets because the IAC can't control it....either have a vac leak somewhere or bad vac line, or bad MAP....

If you have coolant boiling out of the radiator, probably have a head gasket problem......

Sounds like this car has multiple problems....

so it wouldn't be just a sticking iac valve? how would you check the map sensor

found a vacuum leak under the intake

yep changed the intake gasket, its good as new