Whether your Honda Civic is modified or stock, racer or grocery getter, knowing how to adjust Honda Civic Idle Speed can definitely save your some bucks. When your SOHC D15 or D16 engine is having problems with idle, you can use our how to adjust Honda Civic idle speed guide to troubleshoot your problems.
We’ll be walking you through the process on both the 1992-1995 Honda Civic D15, D16Z6 engine as well as the 1996-2000 Honda Civic D16Y8 engine. Before you start our guide, it’s good to know the components that help maintain your idle or engine speed. Depending on your year make and model, there are servos and motors that help keep your engine idling after you’ve turned on your Honda.
Honda Civic Idle Air Controller
There’s the Idle Air Controller, which is commonly found on the back of your Honda intake manifold. This unit is basically a one way valve that allows air to enter into the intake manifold past your throttle body.
There are two coolant lines that connect to this Honda IAC to help quiet the operation of the valve. The part number for a OBDI 1992-1995 Honda Civic Idle Air Controller is 36450-P28-A01. While the OBDII version of this valve is 36450-P2J-J01, and the two units are very similar in design and execution.
Honda Civic FITV
The EACV or Electronic Air Control Valve is a big part of maintaining your Honda Civic idle. If you’ve checked your IAC and your Honda still suffers from a surging idle, check your FITV. This Honda Idle Air Controller or IAC is under the throttle body and incorporates into the throttle body passages.
To locate your Fast Idle Thermo Valve, remove the intake snorkel and locate the FITV beneath your throttle body opening. If your SOHC engine is still having problems, check our guides above on how to check your FITV as well as your IAC. To check this operation, remove your air intake pipe and use your fingers to plug the passages in the lower left hand corner of your throttle body opening.
If your idle surge goes away when you plug this opening, your FITV is bad and must be replaced.
If your idle surge does not go away, unplug your Idle Air Control valve and if that stops your idle surge, your IACV must be replaced. Follow our instructions on how to replace your Honda Civic Idle Air Control Valve.
Need to raise your Honda Civic idle or having problems maintaining idle? You can adjust the base idle by unscrewing or screwing in the Idle screw on your throttle body. This screw allows air to bleed into the passages on the backside of your throttle body, as shown above.
To learn how to adjust Honda Civic idle speed, you will not need to remove anything. With a standard screwdriver, simply locate your throttle body and Idle screw.
Using this idle screw, you can raise and lower your Honda Civic idle as needed. To complete our how to adjust Honda Civic idle speed article, you will need to start your engine and warm it to operating temperatures.
Once your engine has warmed up and your Honda Civic cooling fans kick on, shut off your engine. If you have a timing light that can be connected for accuracy, connect this now to your #1 cylinder spark plug wire.
- Disconnect the two pin EACV connector from the idle controller
- Start SOHC engine with gas depressed slightly ( you may need to keep the engine alive)
- Maintain 1,000 RPM as dictated by your instrument cluster or timing light.
- Make sure you minimize engine load – no lights, no radio, no blower motor, etc.
The target idle speed you are looking for in a manual transmission is 530 ± 50 RPM and with an automatic, you are aiming for 510 ± 50 RPM with the transmission in N or P. Now raise your parking brake and you’re ready to tackle the second half of our how to adjust Honda Civic idle speed guide.
- Shut off engine once you’ve reached target engine speed
- Reconnect your EACV two pin connector
- Disconnect your battery or pull your ECU fuse to reset your Honda Civic ECU.
- Restart the engine and check idle speed.
The target idle speed you are looking for in this second half of the DIY guide is 600 ± 50 RPM and with an automatic, you are aiming for 700 ± 50 RPM. Don’t forget the automatic transmission should be in PARK or NEUTRAL.
Once you’ve reached this point, Honda wants you to turn on your headlights and check RPM again. With headlights on and idling for roughly a minute, you are now aiming for 750 ± 50 RPM and with an automatic, you want 750 ± 50.
The last part of our how to adjust Honda Civic idle speed guide calls for you to turn off the headlights, and now turn on your air conditioning, rear defroster and blower motor at full. With these accessories on, recheck your idle and the values you want are 800 ± 50 RPM and with an automatic, you are aiming for 810 ± 50 rpm.
Congratulations, you have now successfully retrained your Honda Civic idle and fixed any idle surge issues you may have had. Have any questions about our how to adjust Honda Civic idle speed DIY Guide? leave them for us below!