93 Tempo very high idle

Just installed a replacement engine in my son's 93 Tempo, 2.3 litre............can't get the idle down under 2500????? Air bypass valve seems to be operating, TPS and Exhaust valve swapped out with a different set and no change...............suggestions anyone.
Thanks
Tim

[Freewill]

Hey tim I have a 92 tempo 4 cyl with same problem have swapped out theese following parts with no change if you find out please email me @
freewill69@hotmail.com thanks swapped out idle intake air sensor, throttle position sensor,mass air sensor and what i believe is the M.A.P.sensorlittle square box on fire wall hit all vacume lines with starting fluid and no change good luck and if i here ill post here thanks Freewill

[russelldennis]

I have the same problem with my 94 tempo, but only after it has got hot on a longish run.
Recently driving home from Ottawa, I was able to cruise at 90 without touching the gas pedal.
My idle speed is inconsistent though.
It usually idles at around the 1200 mark. . fine.
Sometimes when it's cold it idles slower - at around 800, which I think is low for an auto.

[dcadon]

It has been my experience that the first place to check is the "vacuum" system. Check all lines to ensure no leakage. It is the cheapest "check" and quite often will fix idle problems. Before you go and replace expensive electronics etc, it is essential to make sure the vacuums are working properly. Good Luck

Don in Sarnia

[sandy w]

I have a 1994 Mercury Topaz that had a high idle problem. The culprit was the "IAVC" or idle air control valve. It is located on the manifold next to the EGR valve. It is easy to remove. In most cases the valve just needs cleaning. In my situation the spring inside was stuck and broken. My boyfriend has a 1986 Tempo that no longer runs and I took the IAVC off of his car and mounted it on mine and that's all it was. Good luck.