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 brownjeff Your Own Question

brownjeff
brownjeff, ASE Certified Technician
Category: Dodge
Satisfied Customers: 13885
Experience:  17 years experience, ASE certified, dealership certified, Service Manager for 15 years,
11021861
Type Your Dodge Question Here...
brownjeff is online now
A new question is answered every 9 seconds

2002 Dodge Neon: The fuel tank..fuel gauge..few miles..looked under

Resolved Question:

I have a 2002 Dodge Neon SE. The fuel tank doesn't seem to be venting correctly. The fuel gauge started showing that the car was empty after driving only a few miles, so I looked under the car after driving and was amazed to see that the fuel tank was imploded. I removed the gas cap and with a mad rush of air - the tank went back to its original shape. I replaced the cap and it did the same thing, so I unscrewed the cap and left it loose in the filler neck. That worked to keep the tank vented and the gas gauge worked properly as well. What would cause that kind of vacuum in the tank and why isn't it venting?

Ron Kipple XXX@XXXXXX.XXX
Submitted: 5 years ago.
Category: Dodge
Expert:  brownjeff replied 5 years ago.

There is a control valve in the fuel tank the should regulate the pressure and most likely has failed.

 

Here is some information on it:

 


The emission control principle used in the ORVR system is that the fuel flowing into the filler tube (appx. 1" J.D.) creates an aspiration effect which draws air into the fill tube. During refueling, the fuel tank is vented to the vapor canister to capture escaping vapors. With air flowing into the filler tube, there are no fuel vapors escaping to the atmosphere. Once the refueling vapors are captured by the canister, the vehicle's computer controlled purge system draws vapor out of the canister for the engine to burn. The vapors flow is metered by the purge solenoid so that there is no or minimal impact on driveability or tailpipe emissions.

As fuel starts to flow through the fill tube, it opens the normally closed check valve and enters the fuel tank. Vapor or air is expelled from the tank through the control valve to the vapor canister. Vapor is absorbed in the canister until vapor flow in the lines stops, either following shut-off or by having the fuel level in the tank rise high enough to close the control valve.

The control valve contains a float that rises to seal the large diameter vent path to the canister. At this point in the fueling of the vehicle, the tank pressure increases, the check valve closes (preventing tank fuel from spitting back at the operator), and fuel then rises up the filler tube to shut-off the dispensing nozzle.

If the engine is shut-off while the On-Board diagnostics test is running, low level tank pressure can be trapped in the fuel tank and fuel can not be added to the tank until the pressure is relieved. This is due to the leak detection pump closing the vapor outlet from the top of the tank and the one-way check valve not allowing the tank to vent through the fill tube to atmosphere. Therefore, when fuel is added, it will back-up in the fill tube and shut off the dispensing nozzle. The pressure can be eliminated in two ways:

  1. Vehicle purge must be activated and for a long enough period to eliminate the pressure. 2. Removing the fuel cap and allowing enough time for the system to vent thru the recirculation tube.
brownjeff, ASE Certified Technician
Category: Dodge
Satisfied Customers: 13885
Experience: 17 years experience, ASE certified, dealership certified, Service Manager for 15 years,
brownjeff and other Dodge Specialists are ready to help you

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 AM VERY GLAD THAT I TOOK A CHANCE ON YOUR PROBLEM SOLVING SKILLS. I WAS SUCCESSFUL IN REPLACING THE FUEL PUMP. MY TRUCK RUNS LIKE A CLOCK. IT RUNS LIKE THE DAY I BOUGHT IT. NO LUNGING FORWARD, THE TURBO REACTS THE SECOND I STOMP ON THE GAS, AND IT HAS A LOT MORE POWER AND EVEN SOUNDS BETTER TO ME. IT SAVED ABOUT $500.00 BY DOING THE WORK MYSELF. I GIVE YOU ALL THE CREDIT FOR YOUR DIAGNOSING THE PROBLEM, JUST FROM THE SYMPTONS I GAVE YOU OVER THE e MAIL. I WILL USE YOUR WEB SITE AGAIN AND REFER MY FRIENDS. THANKS SO MUCH FOR THE HELP. TOM WHITTAKER USA
< Last | Next >
  • I AM VERY GLAD THAT I TOOK A CHANCE ON YOUR PROBLEM SOLVING SKILLS. I WAS SUCCESSFUL IN REPLACING THE FUEL PUMP. MY TRUCK RUNS LIKE A CLOCK. IT RUNS LIKE THE DAY I BOUGHT IT. NO LUNGING FORWARD, THE TURBO REACTS THE SECOND I STOMP ON THE GAS, AND IT HAS A LOT MORE POWER AND EVEN SOUNDS BETTER TO ME. IT SAVED ABOUT $500.00 BY DOING THE WORK MYSELF. I GIVE YOU ALL THE CREDIT FOR YOUR DIAGNOSING THE PROBLEM, JUST FROM THE SYMPTONS I GAVE YOU OVER THE e MAIL. I WILL USE YOUR WEB SITE AGAIN AND REFER MY FRIENDS. THANKS SO MUCH FOR THE HELP. TOM WHITTAKER USA
  • Just a quick line to tell you how pleased I am to have my brakes working properly after all this time. Your answer was what I needed. I would certainly recommend you highly. God bless! Rev. Jerry Baysinger Holts Summit, Mo
  • I recently asked a question about my 2005 dodge ram, and I just wanted to let my Expert know that he hit the nail squarely on the head with his answer. I wanted to thank him again. Greg Pittsburgh, PA
  • Just a quick line to tell you how pleased I am to have my brakes working properly after all this time. Your answer was what I needed. I would certainly recommend you highly. God bless! Jerry Holts Summit, MO
  • I was skeptical at first but thought I'd give it a try. I was pleasantly surprised. Your site actually is a quality service that I would recommend to others in a heartbeat. Stan Sayre, PA
  • Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help. Mary C. Freshfield, Liverpool, UK
  • This expert is wonderful. They truly know what they are talking about, and they actually care about you. They really helped put my nerves at ease. Thank you so much!!!! Alex Los Angeles, CA
 
 
 

Meet The Experts:

 
 
 
  • Jerry

    Master Mechanic

    Satisfied Customers:

    1227
    ASE Master tech, 30 years exp. troubleshooter, driveability tech
< Last | Next >
  • http://ww2.justanswer.com/uploads/SU/supermechanic/2013-8-23_03546_500.64x64.jpg Jerry's Avatar

    Jerry

    Master Mechanic

    Satisfied Customers:

    1227
    ASE Master tech, 30 years exp. troubleshooter, driveability tech
  • http://ww2.justanswer.com/uploads/MO/MoparCertified/2012-6-7_4142_mechanic.64x64.jpg Mopar Certified's Avatar

    Mopar Certified

    Dodge Technician

    Satisfied Customers:

    5813
    24 Year Chrysler/Dodge Certified Specialist
  • http://ww2.justanswer.com/uploads/jeep10000/2008-9-18_222938_192601.jpg Chris's Avatar

    Chris

    Shop Foreman

    Satisfied Customers:

    4041
    ASE and Chrysler Certified Master Tech
  • http://ww2.justanswer.com/uploads/ke4ich/2009-08-12_212931_DSC02211.JPG moparfl's Avatar

    moparfl

    ASE Certified Technician

    Satisfied Customers:

    3285
    ASE Master Tech Gold level Chrysler Status 30 years dealership exp
  • http://ww2.justanswer.com/uploads/DO/dodgerench/2012-8-1_1142_IMG3173.64x64.JPG Dodgerench's Avatar

    Dodgerench

    ASE Certified Technician

    Satisfied Customers:

    2480
    30+ years Dodge/Chrysler exp., ASE Master with L1 certification. Driveability/ combustion specialist
  • http://ww2.justanswer.com/uploads/RO/rodcuda/2011-7-25_224114_Donhoff1.64x64.JPG Neal's Avatar

    Neal

    Dodge Mechanic

    Satisfied Customers:

    1870
    30 years experience in Dodge Chrysler and Plymouth
  • http://ww2.justanswer.com/uploads/tsmodie/2009-6-10_144056_tim.jpg Tim Mohr's Avatar

    Tim Mohr

    ASE MASTER TECH

    Satisfied Customers:

    1664
    30 YRS EXPERIENCE, FOREIGN AND DOMESTIC, GAS AND DEISEL