2004 civic 1.7l we just swapped the motor yesterday. the motor was running good before we pulled it. im not sure where to look. i have heard people say clean the iacv with carb cleaner but not sure what part to clean on it? i have heard other honda's idling this way... btw it only idles this way in neutral or park. in drive it feels like its high but smooth. any ideas im all ears.. oh and yes i have checked all vacuum lines and electric connections.

 

Scan it for codes.

The IACV is on the throttlebody, it's #1:

 

Do you have any ceL???

 

mine was doing the same thing when i swapped motors too... i put in on a scanner and the TPS (throttle position sensor) code came up... luckily, i still had my old motor, so all i did was swap throttle bodies instead of just the sensor because i didn't have the tool to take out the sensor. everything is fine now so i would definitely check that out.

 

^^ Yeah, the TPS is riveted in.

Anybody taking bets on what sensor isn't connected or whether it's the ELD?

 

Have you tried resetting the ECU and doing the Idle Relearn?

It's worth trying.

Pull fuse #6 out of the fuse box under the hood. Wait 30 seconds, then reinstall it.

- Turn everything electrical OFF. (radio, wipers, a/c, lights, etc etc)
- Start the car and hold the idle at 3,000 RPM until the radiator fan comes on, or until the coolant has reached 194 degrees.
- Take your foot off the accelerator and let the car idle for five minutes. (if the radiator fan comes on, do not include its run-time in the five minutes)



Your idle should be 700 RPM (+/- 50)


You can also try removing the IACV and cleaning it with carburetor cleaner. Just remove it and clean everything inside it. Also check to make sure there isn't any buildup in the throttle body.

 

do u think it might have a air pocket in the coolant system does it get good heat?

 

This most times happens when people fill the radiator up and put the cap on it without bleeding it.
Did you bleed the system?

 

iacv : just clean the two ports with carb cleaner. carbon builds up inside.

my thought would be double-check tps and make sure no vacuum leaks.