88 non turbo wont idle down
 

Hello, i am new to the forums and abit new to the supra. i have recently purchased an 88 non turbo, the engine runs great but it seems to be having trouble idling down to a normal idle, at times the car idles at 3,000 rpm or more, i have replaced the vacuum lines as well as the iac valve, it doesnt always do it, but 80% of the time my idle is very high, after replacing the iac valve my local mechanic helped me "tweek" my idle back down to roughly 1,000 rpm, a short test drive showed it is still sticking but will go back down to a normal idle as well. when in 5th on the highway and the idle is high its almost like you can hear and feel it go back to the correct idle, engage the clutch it idles at 1,000 rpm. go another mile and engage the clutch its at 3,000 rpm or 2,700 rpm. any ideas would be appreciated, i can post photos and videos as well if it will help.

New To Posting. Not The Forum ;)

Well the idle on these cars r controlled by the computer. Check for error codes stored. Then check the TPS. U didn't play with the little screw of the throttle did u.

Tps test: http://www.cygnusx1.net/Supra/Librar...spx?S=FI&P=101

Code test: http://www.cygnusx1.net/Supra/Librar...ection=FI&P=23