I have a ej22 in my 92 loyale. It runs good other then it idles really high. It usually idles between 1700-1900 all the time, from startup to fully warm. It was showing no codes before I started messing with it. When I unplug the IAC valve, the idle drops down to around 1100 but the engine starts to run really rough and it has a pretty bad dead spot. What would be the procedure to solve such a problem? I already checked for codes after, all it gave me was code 24 from when I unplugged the valve. Thanks for the help.

Could be a lot of things.

 

Was this a swap? Did you try adjusting the throttle cable where it attaches to the manifold?

Investigate the coolant temp sensor, located behind the intake manifold on the passenger side. This has to do with the function of the IAC, depending on how warm the ECu thinks the engine is. The ecu may be thinking the engine is cold, holding the IAC open

could also be a vacuum leak they are the #1 cause of high idle. You can check the coolant temp sensor with a scan tool. It will tell you the temp that the computer is seeing.

mine would idle high until I grounded the pin that told the ecu that it was a manual transmission instead of an automatic.

Investigate the coolant temp sensor, located behind the intake manifold on the passenger side. This has to do with the function of the IAC, depending on how warm the ECu thinks the engine is. The ecu may be thinking the engine is cold, holding the IAC open

 

This very well could be. It seems to run rich and get less then average fuel mileage. I will hook it up to a scan tool and see what that tells me.

Did you clean the IAC? like the others have said check the vac lines, and the MAF, or MAP what ever that year motor has.

mine would idle high until I grounded the pin that told the ecu that it was a manual transmission instead of an automatic.

 

what pin is that?