Rep Power: 0

Okay guys so here's the issue: my 1997 civic ex has a very high idle. Around 1500 rpms. I've cleaned the throttle body, FITV, IACV, replaced dizzy cap, rotor, and put new ngk iridiums in. I did an idle relearn after all of that and still sitting at 1500 rpms. Bought the car with the idle issue so I don't know when or why it started. Engine was rebuilt not too long before I got the car, and has a ton of aftermarket crap on it. Some include: aem cold air intake, bbk throttle body, skunk 2 intake manifold, some sort of aftermarket fuel rail(not sure of brand off top of my head), Otto racing headers, full greddy cat back exhaust, and all upgraded internals. I'm guessing it has bigger fuel injectors too. CEL was on for o2 sensor but I replaced that and now it's just on for o2 sensor heater circuit (downstream sensor(after cat)). Car is also running rich and seems to lose power at low rpms when up to full operating temp. Any suggestions are welcomed, thanks in advance!

 
Rep Power: 0

Car is probably running rich because of bigger fuel injectors. More fuel does NOT equal more power.

Since you have done all the checking and cleaning, the only thing left is a vacuum leak causing your idle problem. Sorry, but you have to find it. Hard to do on a message board.

-SP

 
Rep Power: 0

Yeah I'm planning on getting some stock injectors from a junkyard to see what kinda difference that makes. Looks like I'll have to head to the store, get some carb cleaner, and check all the vacuum lines.

 
Rep Power: 518

If it's idling at 1500 RPM, is it repeatedly surging too?
What's the TPS voltage reading at idle?

What's the operating temperature?

 
Rep Power: 0

It doesn't surge, it sits at a constant 1500. I'll check the tps voltage when I have time. Operating temperature is at about 1/4-3/8, warms up and cools down just as it should.

 
Rep Power: 518

Check the computer live data for coolant temp, not the gauge on the dash.
If the operating temp is too low it may be in cold fast idle mode.

If the TPS is higher than 0.50v it may have the throttle hung open for some reason.
A/M throttle body may need tweaked to close throttle blade more?

Vacuum leaks, stuck IAC,
If it does have a FITV it MUST get hot with good antifreeze flow. I've seen the little coolant hoses and metal fittings get clogged with rust and stopleak and stuff like that and cause fast idle problems.

maybe the ECM memory needs dumped (10 minute battery disconnect with cables shorted) and a relearn done?

 
Rep Power: 367

97 is not a 8th gen or 9th gen car, they much newer than yours.
moved!