I had a 350 put in a couple months back and i scored a pair of 350 injectors, and some 350tbi chips out of a JY for 20$. the chips came from a Caprice Classic, a GMC 350 TBI 1989 truck and a 1990 Chevy 350 TBI truck

These were the only two things left to be done, it previously had 305 injectors and chip on it. After installing the injectors, and one of the chips, the car idles super high, around 1500RPM, i adjusted the idle screw all the way out and now its down to about 1250RPMs, also my SES light is flashing, almost like its getting power on and off, it previously never did this. I tried al the chips and they all have the same effect, flashing SES and high Idle but other than that everything is fine. Im going to replace the bulb and try and pull a code but im kinda lost, i have no idea why it is idling so high and flashing the SES, it only does this with the 350 chips, when i put the 305 injectors on with 305 chip its back to normal, even with the 305 chip it doesnt flash but idles at like 2500. Any ideas on what is going on> i checked for vaccum leaks and i cant find any at all.

 

Fixed the problem

Turned out my IAC was bad, pulled mine and another one off a spare TBI i had lying around and cleaned them up, tried mine, same problem, tried the spare, and shes idling at about 750 now. Pulled the codes while settign the IAC and turns out i had a code 51 on that chip, put in another one from the caprice classic, and still a flashing SES. Turns out all three of the chips i pulled are throwing a code 51 just my luck huh?