Question about 2002 Nissan Xterra

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Changing iac valve

Does anyone know what is involved in changing a IAC valve?

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6 Suggested Answers

emissionwiz
  • 61037 Answers

SOURCE: fast idle after warm up .already changed IAC valve

fast idle is many times caused by a engine intake vacuum leak, use a can of carb spray and spray the top of the engine for leaks, if u hit one u will hear the eng change idle speed, also look for split or leaking vacuum hoses.

Posted on May 20, 2009

yankstorm02
  • 145 Answers

SOURCE: Can any of these 3 problems cause the service engine light to come on? 1.Dirty or faulty fuel filter 2.Bad IAC Valve 3.Fuel pressure regulator

any or all of these problems could illuminate the mil

Posted on May 25, 2009

Molson02536
  • 3854 Answers

SOURCE: IAC Valve Location - 1996 Jeep Grand Cherokee

The idle air control valve is located on the back of the throttle body. It has an oval electrical connector and two torx screws holding it in. Unplug the connector, remove the two screws then lightly tap the body with a soft faced mallet to loosen it from the body. 
Once you have it out and prior to installing a new valve clean the seat inside the throttle body where the idle control fits. This must be very clean! Installation is in the reverse order. 
 To save some cash, pull the valve out and clean it with throttle body cleaner, this usually fixes the problem for quite a while.
Good luck and hope this helps.

Posted on May 28, 2009

  • 14 Answers

SOURCE: IAC control valve. Locato\ion 2002 ford escape

If it's not idling and has problems starting, it's probably the IAC motor. It's located on the throttle body. Follow the airfilter box all the way to the engine, where the rubber flex hose attaches. The throttle body should be the first aluminum part you come to. Attached to the side you'll find small little aluminum part with a small wire harness attached. Unplug it, take the IAC motor off and clean inside with carb cleaner. This should fix the problem with the idle.

Posted on Sep 11, 2009

  • 8 Answers

SOURCE: high idle with new iac valve no difference 1509 trouble code

A vacuum leak can cause high idle.

Posted on Sep 21, 2009

MNfisherman
  • 11896 Answers

SOURCE: 1997 pickup stalls

coil or crank sensor is probably bad

Posted on Oct 06, 2009

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2 Answers

What is an IAC Valve


Google is your friend in such questions.

  • Idle air control actuator - Wikipedia, the free encyclopedia https://en.wikipedia.org/wiki/Idle_air_control_actuator An idle air control actuator or idle air control valve (IAC actuator/valve) ... Idle air control actuator; MAP sensor; Mass flow sensor; Oxygen sensor; Starter motor;
  • how to tell if your iac valve is going bad - YouTube www.youtube.com/watch?v=oNO8GCN8jQA
    • BY TIMMY102345
    • 6 MIN
    • 939K VIEWS
    2009-09-07 · Video embedded · how to tell if your iac valve is going bad timmy102345. ... #372 Better repair method Toyota Camry Idle Air Control Valve - ...
  • 4 Ways to Check an Idle Air Control Valve - wikiHow www.wikihow.com/Check-an-Idle-Air-Control-Valve
    • 525K VIEWS
    2015-12-11 · How to Check an Idle Air Control Valve. ... Again, an idle air control valve can have an issue or fault without triggering a check engine light. 2.


  • There are also videos in this link. How to check and fix.

  • What is an IAC Valve Bing video

    May 12, 2016 | 1992 Toyota Paseo

    1 Answer

    What is code P1507 IN A 1998 ford crow vic


    P1507 - Idle Air Control (IAC) Underspeed Error This DTC is set when the PCM detects engine idle speed that is less than the desired rpm.
    • IAC circuit open
    • IAC circuit short to PWR
    • VPWR to IAC solenoid open
    • Air inlet is plugged
    • Damaged IAC solenoid
    • Damaged PCM
    • The IAC solenoid resistance is from 6 to 13 ohms
    • Disconnect IAC valve and look for no change in engine rpm as an indication of a stuck or damaged valve

    Sep 12, 2015 | Ford Cars & Trucks

    3 Answers

    Need to fix p1504 code on lincoln zs v8 2001


    P1504 Idle Air Control Circuit Malfunction, take off the idle air control and inspect the inside. the pintle inside can get dirty and cause it to get stuck. try cleaning it out with some brake clean and see if it helps. dont spray it ont he electrical connection though.

    Aug 05, 2011 | Lincoln LS Cars & Trucks

    1 Answer

    My ford taurus SE 1999 have 3 codes P1504, P1507 and P1131


    DTC Description Possible Causes Diagnostic Aides P1504 - Idle Air Control (IAC) Circuit Malfunction This DTC is set when the PCM detects an electrical load failure on the IAC output circuit.
    • IAC circuit open
    • VPWR to IAC solenoid open
    • IAC circuit short to PWR
    • IAC circuit short to GND
    • Damaged IAC valve
    • Damaged PCM
    • The IAC solenoid resistance is from 6 to 13 ohms.
      • IAC valve stuck open
      • Vacuum leaks
      • Failed EVAP system
      • Damaged PCM
    • The IAC solenoid resistance is from 6 to 13 ohms.
    P1507 - Idle Air Control (IAC) Underspeed Error This DTC is set when the PCM detects engine idle speed that is less than the desired rpm.
    • IAC circuit open
    • IAC circuit short to PWR
    • VPWR to IAC solenoid open
    • Air inlet is plugged
    • Damaged IAC solenoid
    • Damaged PCM
    • The IAC solenoid resistance is from 6 to 13 ohms
    • Disconnect IAC valve and look for no change in engine rpm as an indication of a stuck or damaged valve
    P1131 - Lack of HO2S-11 Switch, Sensor Indicates Lean A HEGO sensor indicating lean at the end of a test is trying to correct for an over-rich condition. The test fails when the fuel control system no longer detects switching for a calibrated amount of time.
    • Electrical:
      • Short to VPWR in harness or HO2S
      • Water in harness connector
      • Open/Shorted HO2S circuit
      • Corrosion or poor mating terminals and wiring
      • Damaged HO2S
      • Damaged PCM
    • Fuel System:
      • Excessive fuel pressure
      • Leaking/contaminated fuel injectors
      • Leaking fuel pressure regulator
      • Low fuel pressure or running out of fuel
      • Vapor recovery system
    • Induction System:
      • Air leaks after the MAF
      • Vacuum Leaks
      • PCV system
      • Improperly seated engine oil dipstick
    • EGR System:
      • Leaking gasket
      • Stuck EGR valve
      • Leaking diaphragm or EVR
    • Base Engine:
      • Oil overfill
      • Cam timing
      • Cylinder compression
      • Exhaust leaks before or near the HO2S(s)
    A fuel control HO2S PID switching across 0.45 volt from 0.2 to 0.9 volt indicates a normal switching HO2S.

    Mar 16, 2011 | 1999 Ford Taurus

    1 Answer

    What does code p1506 mean?


    P1506 - Idle Air Control (IAC) Overspeed Error This DTC is set when the PCM detects engine idle speed that is greater than the desired rpm.
    • IAC circuit short to GND
    • Damaged IAC valve
    Disconnect IAC valve and look for little or no change in engine rpm as an indication of a stuck or damaged valve.

    Oct 17, 2010 | 2000 Mercury Sable

    1 Answer

    Diagnostics test says idle air control underspeed error? how do i fix 1999 ford explorer


    change the idle air control valve.

    Idle Air Control (IAC) Valve OPERATION The Idle Air Control (IAC) valve controls the engine idle speed and dashpot functions. The valve is located on the side of the throttle body. This valve allows air, determined by the Powertrain Control Module (PCM) and controlled by a duty cycle signal, to bypass the throttle plate in order to maintain the proper idle speed. Fig. 1: Typical Idle Air Control (IAC) valve which is mounted to the throttle body - cutaway view shows air bypass direction 89684g16.gif
    --- REMOVAL & INSTALLATION
    1. Disconnect the negative battery cable. To remove the IAC valve, first disconnect the negative battery cable, then the IAC wire harness plug 89684p03.jpg
      Next, remove the two IAC valve attaching bolts . . . 89684p04.jpg
      . . . and pull the valve from the intake manifold 89684p05.jpg

    2. Disengage the wiring harness connector from the IAC valve.
    3. Remove the two retaining screws, then remove the IAC valve and discard the old gasket. To install: When installing the valve, always discard the old gasket and install it using a new one 89684p06.jpg

    4. Clean the IAC valve mounting surface on the throttle body of old gasket material.
    5. Using a new gasket, position the IAC valve on the throttle body. Install and tighten the retaining screws to 71-106 inch lbs. (8-12 Nm).
    6. Attach the wiring harness connector to the IAC valve.
    7. Connect the negative battery cable.
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    Oct 15, 2010 | 1999 Ford Explorer

    1 Answer

    Will not idle, will run if you push on the gas and hold it. No engine light indicator


    you need to clean your idle air control valve ( or replace it) Spray carb cleaner does a nice job of cleaning it.

    This tutorial is from autozone.com


    OPERATION



    The Idle Air Control (IAC) is a bi-directional motor driven by two coils. The purpose of the IAC valve is to control engine idle speed, while preventing stalls due to changes in the engine load. The IAC valve, mounted in the throttle body, controls bypass air around the throttle plate. The PCM controls engine idle speed by adjusting the position of the IAC motor pintle. The PCM pulses current to the IAC coils in small steps (counts) to extend the pintle into a passage in the throttle body to decrease air flow. The PCM reverses the current pulses to retract the pintle, increasing air flow. This method allows highly accurate control of idle speed and quick response to changes in engine load. If RPM is too low, the PCM will retract the IAC pintle, resulting in more air being bypassed around the throttle plate to increase RPM. If the RPM is too high, the PCM will extend the IAC pintle, allowing less air to be bypassed around the throttle plate, decreasing RPM.



    0900c15280217cd2.jpg enlarge_icon.gifenlarge_tooltip.gif

    Fig. Typical Idle Air Control (IAC) valve components
    During idle, the proper position of the of the IAC pintle is calculated by the PCM based on the battery voltage, coolant temperature, engine load and engine RPM. If the RPM drops below a specified value, and the throttle plate is closed (TP sensor voltage is between 0.20-0.74), the PCM senses a near stall condition. The PCM will then calculate a new IAC pintle position to prevent stalls.
    If the IAC valve is disconnected and reconnected with the engine running, the idle RPM will be wrong. In this case, the IAC has to be reset. The IAC resets when the ignition switch is cycled ON and then OFF . When servicing the IAC, it should be disconnected or connected with the ignition switch OFF in order to keep from having to reset the IAC valve.
    The position of the IAC pintle affects engine start up and the idle characteristics of the vehicle. If the IAC pintle is fully open, too much air will be allowed into the manifold. This results in high idle speed, along with possible hard starting and a lean air/fuel ratio. A Diagnostic Trouble Code (DTC) may set. If the IAC pintle is stuck closed, too little air will be allowed in the manifold. This results in a low idle speed, along with hard starting and a rich air/fuel ratio. Again, a Diagnostic Trouble Code (DTC) may set. If the IAC pintle is stuck part way open, the idle may be high or low and will not respond to changes in engine load.


    TESTING



    As with most all engine control sensors used in your vehicle, a thorough and proper test can only be performed by a qualified technician using a scan tool to read the data stream from the PCM. There are a few items a non-professional should check before taking the vehicle to a qualified technician for diagnosis and repair.



    Check for a poor connection at the PCM or IAC motor. Inspect the harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals and poor terminal-to-wire connection. Inspect for a damaged wiring harness, especially if heavy work has recently been performed (intake manifold removal, engine removal, etc.) where the throttle body has been disturbed. Inspect for a restricted air intake system. Check for a possible collapsed air intake duct, restricted air filter element or foreign objects blocking the air intake system. Inspect the throttle body. Check for objects blocking the IAC passage or throttle bore. Excessive deposits, especially on high-mileage engines, can build up in the IAC passage and on the IAC pintle. Excessive deposits can also build up on the throttle plate, so check for a sticking throttle plate. Check for vacuum leaks such as disconnected hoses, leaks at the EGR valve and EGR pipe to the intake manifold, leaks at the throttle body, faulty or incorrectly installed PCV valve, leaks at the intake manifold brake booster hose connection, etc.



    REMOVAL & INSTALLATION



    1. Disconnect the negative battery cable.
    2. Detach the electrical connector from the IAC valve.
    3. Remove the 2 attaching screws and remove the IAC valve from the engine. Remove the O-ring from the housing.

    To install:



    0900c15280217cd3.jpg enlarge_icon.gifenlarge_tooltip.gif

    Fig. The Idle Air Control (IAC) valve is mounted on the throttle body-3.8L (VIN K) engine shown, others similar


    NOTE Before installing a new IAC valve, measure the distance that the valve is extended. The measurement should be made from the motor housing to the end of the valve cone (pintle). The distance should be no greater than 1 1 / 8 inch (28mm). If the pintle is extended too far, adjustment is required, otherwise damage may occur when the IAC valve is installed. Adjust the IAC valve by compressing the pintle to achieve the correct length.


    1. Use a new O-ring, install the IAC valve and tighten the retaining screws to 18 inch lbs. (2 Nm).
    2. Attach the electrical connector.
    3. Connect the negative battery cable.
    4. The PCM will reset the IAC valve the next time the ignition switch is turned ON and then OFF .
    5. Start the engine and allow to warm to operating temperature to check idle quality.

    Oct 13, 2010 | 2000 Pontiac Grand Prix

    3 Answers

    2001 FORD F250 5.4L HIGH IDLE PROBLEMS.CHANGED IAC AND STILL THE SAME


    High idle
    Changed IAC still the same, shown on scanner IAC 50-60 %, if it set to 40% the Idle is ok. What cause the PCM to set IAC too high? Is any one know?

    Apr 18, 2010 | 2001 Ford F250 Super Duty Super Cab

    1 Answer

    Where is the iac valve and how much labor is


    It is right there with the throttle body. It consist of 2 bolts, cleaning. reinstalling o-ring and part. It's a simple task that would cost you $150 in labor.

    Feb 26, 2010 | 2003 Honda Pilot

    2 Answers

    I need to know where the idle adjustment screw is on a 92 Saturn SL1 and what wrench to use.


    its located on the throttle body connected to your air intake manifold where your throttle cable connects on the throttle body there is a adjustment screw connected there

    Nov 03, 2009 | 1992 Saturn SL1

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