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 AUT0PR0 Your Own Question

AUT0PR0
AUT0PR0, Auto Service Technician
Category: Car
Satisfied Customers: 130
Experience:  35 YEARS AUTOMOTIVE REPAIR EXPERIENCE, OWN SHOP, ASE MASTER CERTIFIED L1 ADVANCED DIAGS. CERTIFIED
Type Your Car Question Here...
AUT0PR0 is online now
A new question is answered every 9 seconds

1995 Ford Windstar: Lx..ErrorcodesP0171and P0174-system..lean..cool

Customer Question

1995 Ford Windstar Lx, 3.8 l engine.
Error codes P0171 and P0174 - system lean - both banks
This error only occurs after I start driving the car from a cold or cool start. It sets at about the time of upshift from 2 to 3 and accelerating. I reset the codes after pulling to the curb, start driving again and they never set again until the engine is off and cools down. Same thing happens upon starting out again. If I shut down for a few minutes and start out again, no codes.

Engine has 250,000 miles on it. Fuel pump is new - 40 psi at Schrader valve with pressure regulator hose disconnected and plugged. MAF sensor was replace 10,000 miles ago. Fuel pressure regulator replaced about 5,000 miles ago. Plugs are new, wires are not. EGR valve replaced about 30,000 miles ago, differential pressure sensor/controller was not. all four heated O2 sensors were replaces about 10,000 miles ago and did not change problem.

Any Ideas?
Submitted: 7 years ago.
Category: Car
Expert:  AUT0PR0 replied 7 years ago.
a common problem with these vehicles that causes codes P0171 & P0174 (system lean bank 1 & 2 ) is the rubber seals on the intake plenum isolator bolts. these are the bolts that secure the plastic lower intake plenum to to the intake manifold. they become hard and brittle and and allow vacuum leakage. I've replaced quite a few of them for the same problem. The ford part # XXXXX XXXXX They come in a package of eight and the repair normally takes about an hour and a halve to do.
Customer: replied 7 years ago.
Doesn't sound like we're talking about the same engine here. The throttle body is mounted to the intake manifold on four studs with a gasket between the manifold and the throttle body. The air filter is connected through a combination of plastic tube and two rubber hose, about 4 inches in diameter. The MAF is mounted in the tube right next to the air filter.

Your answer implies a vacuum leak somewhere but I sure can't find it. Vacuum readings are steady. The PCV was replaced a week ago and the crankcase vent tubes are sealed well.

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