How JustAnswer Works:

  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.

Ask Mike V. Your Own Question

Mike V.
Mike V., Auto Service Technician
Category: Car
Satisfied Customers: 20350
Experience:  25 years of experience, Certified Subaru Technician and Nissan factory trained.
2921078
Type Your Car Question Here...
Mike V. is online now
A new question is answered every 9 seconds

I have a 99 Ford Taurus SE with an idling problem.

Customer Question

I have a '99 Ford Taurus SE with an idling problem. When I get going on the road, everything is fine, but at a redlight, drivethrough, etc., the idle begins to diminish and, eventually, the car dies. The only thing I have really done to the system is change the fuel filter (along with all the other general maintenance of oil change, filter, air filter, etc.) What are some things I can do to fix this problem?
Submitted: 6 years ago.
Category: Car
Expert:  Mike V. replied 6 years ago.

Hi there!It is likley the IAC valve.Sometimes it gets covered with carbon and the pintal inside cannot move to make the adjustments.You can usually take it off and clean everything up with carb cleaner and that will allow the pintal to move properly.Here is some info.Hope it helps!Thanks

OPERATION

See Figure 1

Click image to see an enlarged viewFig. 1: IAC valve assembly

The Idle Air Control (IAC) valve adjusts the engine idle speed. The valve is located on the side of the throttle body. The valve is controlled by a duty cycle signal from the PCM and allows air to bypass the throttle plate in order to maintain the proper idle speed.

Do not attempt to clean the IAC valve. Carburetor tune-up cleaners or any type of solvent cleaners will damage the internal components of the valve.

TESTING

See Figure 2

Click image to see an enlarged viewFig. 2: The IAC can be monitored with an appropriate and Data-stream capable scan tool

  1. Turn the ignition switch to the OFF position.
  2. Disconnect the wiring harness from the IAC valve.
  3. Measure the resistance between the terminals of the valve.

Due to the diode in the solenoid, place the ohmmeter positive lead on the VPWR terminal and the negative lead on the ISC terminal.

  1. Resistance should be 6-13 ohms.
  2. If resistance is not within specification, the valve may be faulty.

REMOVAL & INSTALLATION

See Figures 3 through 9

Click image to see an enlarged viewFig. 3: IAC valve mounting-3.0L OHC (4 valve) engine Click image to see an enlarged viewFig. 4: Detach the IAC valve connector Click image to see an enlarged viewFig. 5: The IAC valve is retained by two bolts Click image to see an enlarged viewFig. 6: Remove the two IAC valve retaining bolts and... Click image to see an enlarged viewFig. 7: ... remove the IAC valve from the intake manifold Click image to see an enlarged viewFig. 8: Thoroughly clean the IAC valve mounting surfaces Click image to see an enlarged viewFig. 9: Always use a new IAC valve gasket when installing the IAC valve onto the intake manifold

  1. Disconnect the negative battery cable.
  2. Remove the air cleaner inlet tube and the throttle cover, if necessary.
  3. Disconnnect the wiring harness from the IAC valve.
  4. Remove the two retaining bolts.
  5. Remove the IAC valve and discard the old gasket.

To install:

  1. Clean the gasket mating surfaces thoroughly.
  2. Using a new gasket, position the IAC valve on the throttle body.
  3. Install and tighten the retaining bolts to 71-106 inch lbs. (8-12 Nm).
  4. Connect the wiring harness to the IAC valve.
  5. If removed, install the air cleaner tube and throttle cover.
  6. Connect the negative battery cable.
Mike V., Auto Service Technician
Category: Car
Satisfied Customers: 20350
Experience: 25 years of experience, Certified Subaru Technician and Nissan factory trained.
Mike V. and 12 other Car Specialists are ready to help you
Customer: replied 6 years ago.
I cleaned and checked the AIC valve; the ohm meter read 10.1. When I started the engine back up, I could hear something that sounded like air escaping under pressure. I don't know what the hell is going on here...
Expert:  Mike V. replied 6 years ago.
I can assume then you are still having problems with the car?If you can hear air leaking then you may have a vaccum lleak.To locate it you can spray carb cleaner around the area of the leak.With the car running this should produce a rise in the rpms.When that happens you will be in the area of the leak.Let me know

JustAnswer in the News:

 
 
 
Ask-a-doc Web sites: If you've got a quick question, you can try to get an answer from sites that say they have various specialists on hand to give quick answers... Justanswer.com.
JustAnswer.com...has seen a spike since October in legal questions from readers about layoffs, unemployment and severance.
Web sites like justanswer.com/legal
...leave nothing to chance.
Traffic on JustAnswer rose 14 percent...and had nearly 400,000 page views in 30 days...inquiries related to stress, high blood pressure, drinking and heart pain jumped 33 percent.
Tory Johnson, GMA Workplace Contributor, discusses work-from-home jobs, such as JustAnswer in which verified Experts answer people’s questions.
I will tell you that...the things you have to go through to be an Expert are quite rigorous.
 
 
 

What Customers are Saying:

 
 
 
  • I would (and have) recommend your site to others I was quite satisfied with the quality of the information received, the professional with whom I interacted, and the quick response time. Thanks, and be sure that I'll be back whenever I need a question answered in a hurry. Stephanie P Elm City, NC
< Last | Next >
  • I would (and have) recommend your site to others I was quite satisfied with the quality of the information received, the professional with whom I interacted, and the quick response time. Thanks, and be sure that I'll be back whenever I need a question answered in a hurry. Stephanie P Elm City, NC
  • used your service this weekend with "Trecers" help. thank you ,thank you, thank you. replaced an A/C fan motor. Local Auto Zone had part. $15.00 "tracer" fee and $40.00 for parts, I saved several hundreds of dollers at a shop. i will recommend you and use you in the future. David L. Richmond, TX
  • 9 dollars, 2 hours of my time, and I drove away. Your diagnosis was right on the mark. Thank you so much. Phil Marysville, CA
  • Lurch. Thank you very much. I had real doubts about this website but your promptness of response, quick followup and to the point answer with picture was incredible. Charles Walnut Creek, CA
  • As a single woman, I really appreciate an excellent and affordable opinion.
    Thank you Geordie, I will not hesitate to contact justanswer in the future!
    Sue Charleston, WV
  • Another great insight to what may be the problem. I will have my mechanic take a look at it tomorrow. Thanks again, Frank...you do indeed know your stuff. Jim Castleberry, FL
  • Excellent reply, and also very quick. Really sounds like the Expert knows what he is talking about. I will be back to use your service when I need more help with my RV. Dutch USA
 
 
 

Meet The Experts:

 
 
 
  • Chris (aka-Moose)

    Technician

    Satisfied Customers:

    846
    16 years of experience
< Last | Next >
  • http://ww2.justanswer.com/uploads/MU/muddyford/2012-6-13_1204_1.64x64.png Chris (aka-Moose)'s Avatar

    Chris (aka-Moose)

    Technician

    Satisfied Customers:

    846
    16 years of experience
  • http://ww2.justanswer.com/uploads/TE/TedG/2012-6-15_14759_avaLarge.64x64.jpg Ted G.'s Avatar

    Ted G.

    ASE Certified Technician

    Satisfied Customers:

    1596
    20 years auto repair experience, ASE Master Tech, Mechanical Failure consultant, Expert Witness
  • http://ww2.justanswer.com/uploads/joecamel90/2008-11-13_03615_head_shot.jpg George H.'s Avatar

    George H.

    ASE Certified Technician

    Satisfied Customers:

    1311
    ASE Master Tech 15+ yrs, AAS Automotive Technology, Factory trained Asian specialist
  • http://ww2.justanswer.com/uploads/AM/amedee/2013-10-24_23656_Amedee1.64x64.jpg Amedee's Avatar

    Amedee

    ASE Master Tech

    Satisfied Customers:

    2367
    ASE Master Tech advanced level specialist
  • http://ww2.justanswer.com/uploads/SU/supermechanic/2013-8-23_03546_500.64x64.jpg Jerry's Avatar

    Jerry

    Master Mechanic

    Satisfied Customers:

    1906
    ASE master, 30+ years. All makes and models. Trouble shooter, shop forman, service manager
  • http://ww2.justanswer.com/uploads/CR/crzydrvr00/2013-11-3_12123_246347.64x64.jpg Richard's Avatar

    Richard

    ASE Certified Technician

    Satisfied Customers:

    942
    12 years Ford Lincoln/Mercury Jaguar dealership as a technician and shop foreman reparing all makes
  • http://ww2.justanswer.com/uploads/ST/Steve7654/2012-6-5_215929_japic800x660.64x64.jpg Steve's Avatar

    Steve

    Auto Service Technician

    Satisfied Customers:

    1980
    25+ yrs experience as a professional working technician; ASE L1 master technician