Here's the deal, it should be very simple.

1994 Acura Vigor, 2.5L motor.

Removed factory airbox (1 screw, 2 bolts).

Installed Apex'i air filter.

Disconnected power x 20 minutes.

Started car up.

Now at idle, even when car is warm, the car idles at 500 RPM. Does not surge, but just stays low.

Ideas?

 

have you tried to replace it again witht the stock one to see if the problem persists?

Thats number one to do on the list..although i should say replacing a filter should not do this.

But maybe since the filter is letting more air through and its not that much lower you could probably get away with just adjusting the idle screw on the TB. I believe idle should be around 800rpm or so.

 

Ater the power has been disconnected that long, the ECU needs to relearn the idle. Typically, you start the car and do not touch the accelerator until the engine reaches operating temperature.