Why is my civic idling high?
Vacuum Leak: On any engine, a vacuum leak will cause a high engine idle as the oxygen sensor detects lean operation and the engine computer then tries to compensate, which can result in abnormal idle. Malfunctioning Throttle: A malfunctioning throttle system can cause both a high or low idle as well as an engine stall.
What should the idle speed be on a Honda Civic?
Turn off the car. Reconnect the IACV, and reset the ECU by unplugging the back-up fuse. Restart the engine, and the idle speed should be in the 620 to 720 rpm range. Replacing the entire throttle body is probably the best option if this is the case, but that’s an expensive fix.
How can I check the idle air control?
To perform a rough check of the idle air control, remove the valve while reconnecting the wiring harness. While observing the valve with a flashlight, turn the key to the “ON” position, (DO NOT START ENGINE.) the valve should move slightly.
Why does an erratic idle set a MAP sensor code?
An erratic idle CAN set a MAP sensor code however which is why I mention it. The reason for this is because the MAP is in essence a vacuum gauge so if it’s gets strange readings from a fluctuating idle it can set a MAP sensor code.
Can a bad IAC cause a DTC to set?
If you do not hear a change in RPMs, do not assume the IAC is bad until you do further testing. Also, this test may cause DTCs to set. With the engine off, unplug the IAC. Then start the engine and listen for an idle speed that’s either too high, too low, or fluctuating.
Turn off the car. Reconnect the IACV, and reset the ECU by unplugging the back-up fuse. Restart the engine, and the idle speed should be in the 620 to 720 rpm range. Replacing the entire throttle body is probably the best option if this is the case, but that’s an expensive fix.
What do you need to know about a throttle position sensor?
What Is a Throttle Position Sensor? This vital sensor allows your engine to maintain a proper amount of air. This feature is dependent on the throttle valve. When you press down on the gas pedal, your throttle body unit’s valve opens.
Where is the idle air control valve located?
The valve is a major management component of the engine which will either decrease or increase the number of revolutions per minute, depending on what the current operating conditions call for. The valve is connected to the throttle body next to the intake manifold.
What causes a lumpy idle on a Honda Civic?
A failing IACV will result in a hunting idle (where the revs go up and down without accelerator input) or a lumpy idle (where the idle will fall until the ECU compensates and rises it again repeatedly). To fix this, either replace the IACV or clean it. Figure 2. Idle air control valve