Question about 1989 Honda Prelude

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97 acura integra idle rough when cold and

I replaced the idle air control valve

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Where are the rpm's at when its idling cold?

if the cold idle is below 1500 rpm. adjust it by tightning/loosing the intake spring located on the intake manifold.

if it does it reguardless of rmp. replace the spark plugs.

Posted on Aug 14, 2009


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Posted on Jan 02, 2017


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What is an IAC Valve

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  • Idle air control actuator - Wikipedia, the free encyclopedia 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
    • BY TIMMY102345
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    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
    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

    How to fix fault code P1507

    Possible causes
    - Faulty Idle Air Control (IAC) valve
    - Idle Air Control (IAC) valve harness is open or shorted
    - Idle Air Control (IAC) valve circuit poor electrical connection
    What does this mean? Tech notes
    The P1507 code means that the engine idle is out of factory specification. Sometimes the Idle Air Control (IAC) may have carbon built up. Disconnect the car battery, remove the valve, clean, re-install valve, and drive the vehicle for about 5 minutes with the headlights and A/C ON to get the idle relearned.
    If the problem persist, the IAC valve may need to be replaced.

    Read more:

    Nov 22, 2015 | 2000 Ford Ranger SuperCab

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    96 acura idle rough an when I'm sitting still an turn the steering wheel the car dies please help.u can email @ thank u

    a vacuum leak. cold fuel system is enriched. any extra load could cause it to die. what TL? 2.5? idle air control valve? TPS ? check for codes!!

    Jun 04, 2014 | 1996 Acura TL Series

    1 Answer

    1992 acura integra wont stay running

    Try the procedure below.

    Here are the most common causes of idle surge, stalls at stops, slow idle speed, erratic idle speed, rough idle and engine hesitation (and other problems), it is in most cases the idle speed control air-bypass valve and or throttle valve and upper intake, these area's get full of gunk and combustion residue over the miles and cause idle issues (stalls, low idle) like yours, Get a can of intake cleaner from any local parts store, not carb spray, intake cleaner, it is made by a company called CRC, remove the air intake hose to the engine, hold the idle high so the engine won't stall, then spray the can of cleaner into the intake while keeping the engine running, use at least 1/2 the can, shut down the engine and disconnect the battery for 5 minutes, then restart and complete a number of mixed driving cycles, town, freeway, stop and go etc., after a few days the problem will go away as the system will relearn to the clean intake

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    98 dodge ram 1500 5.2 the truck will start but it will not idle.

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    When i turn on the ac the idle goes low and the the car vibrates. When i turn off the ac the car stop vibrating.


    The Idle Air Control (IAC) valve controls the amount of air that bypasses the throttle valve, which controls the engine idle speed. The IAC valve consists of windings, an armature, a return spring, and a rotary slide. The engine control module (ECM) pulses the voltage to the winding, the opposing forces on the armature by the return spring cause it to maintain a fixed position, adjusting the amount of bypass air to maintain the correct idle speed.

    Removal & Installation

    1. Turn the ignition switch to the OFF position.
    2. Disconnect the idle air control valve harness electrical connector.
    3. Using a suitable tool, remove idle air control valve.
    4. Installation is in reverse order of removal.


    Checking Idle Air Control Valve (IAC) Triggering

    1. Check IAC valve is electrically OK.
    2. Slide up boot on the IAC valve connector.

    0900c152801c00a1.jpg enlarge_icon.gifenlarge_tooltip.gif

    Fig. IAC Connector

    1. Use scan tool 'Output Diagnostic Test Mode' function 03 to trigger the IAC valve - N71.
    2. Connect VAG 1527B voltage tester, or equivalent, between terminal 1 and engine ground (GND). Voltage tester must flash.
    3. Connect VAG 1527B voltage tester, or equivalent, between terminal 2 and battery positive voltage (B+). Voltage tester must light up.
    4. If specified results are not obtained:
      1. Connect VAG 1598/19 test box, or equivalent, to ECM harness connector.
      2. Check the wiring between harness and connector terminal 1 (in engine compartment) to test box socket D11 . Then check the wiring between harness connector terminal 2 and test box socket D9 using wiring diagram. Repair as necessary.
      3. If the wiring is okay, but triggering still does not occur, replace the ECM.
      4. If the triggering signal and the wiring are okay and the valve does not react, replace the IAC valve.

    Checking Mechanical Function
    1. Remove the idle air control (IAC) valve.
    2. Visually check the surface of the rotary slide (arrow) for signs of wear.

    0900c152801c00a2.jpg enlarge_icon.gifenlarge_tooltip.gif

    Fig. Showing the IAC Valve

    WARNING Do NOT check for ease of movement by prying on the rotary slide with a screwdriver or other tools that could cause scratching or other damage.

    1. Reconnect the IAC valve, while still removed, to the harness connector.
    2. Use scan tool 'Output Diagnostic Test Mode' function 03 to trigger IAC valve - N71.
    3. Check whether rotary slide moves freely from stop to stop.
    4. If there are signs of scoring, or if the rotary slide does not move freely in both directions, replace the IAC valve.
    5. If the IAC valve does not respond (not triggered) during the Output Diagnostic Test Mode, check triggering.

    Resistance Test
    1. Remove the idle air control valve harness connector.
    2. Use a suitable Digital Multimeter (DMM) to measure the resistance between the 2 terminals of the idle air control valve.
    3. The correct measurement should be 7-11 ohms. If not, replace the idle air control valve.

    NOTE At room temperature, the resistance value will be lower. The resistance value will be higher if the Idle Air Control (IAC) valve is measured at under-hood operating temperatures.
    1. Reconnect the idle air control valve harness connector.
    2. The idle air control valve should hum and vibrate slightly when the ignition is turned 'ON'. If not, the ECM or harness may be defective.

    Testing with VAG1551:
    1. Remove the idle air control valve harness connector.
    2. Connect the VAG 15278 LED tester to terminals 1 and 2 of the harness connector using the jumpers from VW 1594 adaptor kit.
    3. Turn ignition ON, perform steps from output DTM (Diagnostic Test Mode) to activate the IAC valve (N71) LED tester must blink.
    4. If tester does not blink, check wiring using VAG 1598 pin out box, electrical checks, step 26. Repair as necessary.
    5. If wiring is okay, replace the ECM.
    6. If LED tester blinks but the IAC valve does not operate, replace the IAC valve.

    Feb 15, 2011 | 2000 Volkswagen Jetta TDI

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