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 sean Your Own Question

sean
sean, UK Ford Master Technician
Category: UK Ford
Satisfied Customers: 2871
Experience:  Ford Master Tech since 2001 & MOT tester mechanic since 1984.
Type Your UK Ford Question Here...
sean is online now
A new question is answered every 9 seconds

Ford transit tornio: hi i have a trouble code p215A the van

Resolved Question:

hi i have a trouble code p251A the van goes in to limp home mode when you cycle the ign fault clears on the dash and drives as it should
Submitted: 2 years ago.
Category: UK Ford
Expert:  sean replied 2 years ago.

Hello, I hope I can offer you some assistance.

The fault code P251A won't be the reason for the loss of power, this fault code relates to a Power Take Off (PTO) circuit, this fault will have been logged in error from a previous software update on the engine management control module.

You need to have the software checked and updated as necessary but make sure all necessary parameters are entered when required.

With regard to the actual loss of power check for stored fault codes when the fault occurs. If no fault codes are stored then you need to check live data from the engine management when the fault occurs, check the fuel pressure demanded and actual any discrepancy of around 20 bar will result in the engine management switching to Limited Operating. Check that the pressure relief valve hasn't activated in the end of the fuel rail if it has then the engine management won't be able to control the fuel pressure. Replace the fuel filter if it hasn't been replaced recently, if possible check the injector operation as a faulty injector will cause fuel pressure concerns.

Check the EGR valve operation, if you can't hear it cycle at ignition off it may have seized although this normally leaves a fault code.

Let me know if I can assist further and I'll reply to you as soon as I'm able to.

Best wishes and merry Christmas,

Sean.

Customer: replied 2 years ago.

hi sean,

the fuel filter is new about 3 months a go my solus pro reads in kpa can you please tell me the paramters for fuel pressure and how to test the sensor

Expert:  sean replied 2 years ago.

Hello again,

the fuel pressure at idle should be around 300bar, you should be able to see the demanded fuel pressure to check the actual pressure against this. If you disconnect the fuel pressure sensor from the rail you should get a maximum fuel pressure reading, if not there may be a wiring concern. 1 bar is equal to 100kpa.

As I said originally if there is a discrepancy between the pressure demanded and actual then the fuel rail pressure relief valve may have activated.

As the only code you have is the PTO as I said earlier make sure the engine management software is up to date.

Let me know if I can assist any further.

Best regards,

Sean.

Customer: replied 2 years ago.

hi, yes the software was updated in september 2011

 

the fuel pressure at idle is around 350 PSI

 

but there is a huge difference between psi and bar is it defently 300 bar or 300 psi on the F P Rail

 

i disconected the FPS and what you said would happen did

 

how do i test the fuel rail pressure relief valve has been activated????

 

the engine does not go in to limited opperating mode all the time - it is very sporadic when it hapens mainly when the mini bus has 9 passengers in and some luggage in the boot dont know weather it is a co-incidence or related to extra weight and more throttle useage ???

 

 

Expert:  sean replied 2 years ago.

Hello again,

I think the reading you have is incorrect 300PSI is only around 20 bar which the engine wouldn't even start on, the target pressure to start is at least 250 bar and at idle is around 300 bar. The figures I give to you are in bar for certain.

If you think, 300 PSI pressure would not even be enough to overcome the compression pressure in the cylinder (TDCi compression should be around 350 to 370 PSI) hence the extreme pressures involved in the fuel system the pressure can exceed 600 bar if not controlled.

If you can read live data while driving then check the fuel pressure as follows,

select second gear when driving allow the engine to come to idle in second gear then accelerate hard up to 4000 RPM then release the throttle observe the fuel pressure when you do this if the pressure reaches 500 bar then the fuel pressure relief valve has opened.

From your description I would say it is a fuel pressure concern, the heavier the load on the engine the higher the required fuel pressure, if the fuel pressure isn't available in the preset time then the engine management switches to limited operating which is when you get the lack of power.

Double check the fuel pressure reading as I say 20 bar wouldn't start the engine.

Let me know,

Regards,

Sean.

sean, UK Ford Master Technician
Category: UK Ford
Satisfied Customers: 2871
Experience: Ford Master Tech since 2001 & MOT tester mechanic since 1984.
sean and other UK Ford Specialists are ready to help you
Customer: replied 2 years ago.

hi sean!

 

i have done the test you sugested

here are the results

 

at 4000 rpm in 2nd gear = 169120 kpa which converts to 1691.2 bar

 

what do you think?

 

has the valve been activated

the driver has noticed a drop in fuel ecomomy is this related?

 

 

Expert:  sean replied 2 years ago.

Hello again,

as the pressure reaches 1600 bar then I would say the relief valve is OK as if the relief valve opens the pressure is normally stable at 500 bar.

Is the fault evident when you test the van at all?

Regards,

Sean.

Customer: replied 2 years ago.

no every time i have driven the vehicle i have not been able to replicate the symtoms

 

what is injector clylinder ballance?

 

injector cylinder 1 and 4 is at 2 and 2 and 3 are at 0 is this correct?

Customer: replied 2 years ago.

no every time i have driven the vehicle i have not been able to replicate the symtoms

 

what is injector clylinder ballance?

 

injector cylinder 1 and 4 is at 2 and 2 and 3 are at 0 is this correct? #

 

thanks simon

Expert:  sean replied 2 years ago.

Hello again,

injector balance is measuring the adjustment of the fueling for the injectors normally the readings are around 0.9 to 2 so I would say that these were OK.

You really need to measure things like the fuel pressure when the fault occurs, this can mean using the van over several days. A reading that is correct now may well show incorrectly when the fault occurs.

Let me know if I can help further.

Regards,

Sean.

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:

 
 
 
  • 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
< Last | Next >
  • 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
  • Thank you for all your help. It is nice to know that this service is here for people like myself, who need answers fast and are not sure who to consult. GP Hesperia, CA
  • I couldn't be more satisfied! This is the site I will always come to when I need a second opinion. Justin Kernersville, NC
  • Just let me say that this encounter has been entirely professional and most helpful. I liked that I could ask additional questions and get answered in a very short turn around. Esther Woodstock, NY
  • Thank you so much for taking your time and knowledge to support my concerns. Not only did you answer my questions, you even took it a step further with replying with more pertinent information I needed to know. Robin Elkton, Maryland
  • He answered my question promptly and gave me accurate, detailed information. If all of your experts are half as good, you have a great thing going here. Diane Dallas, TX
 
 
 

Meet The Experts:

 
 
 
  • Trev

    UK Ford Car Mechanic

    Satisfied Customers:

    271
    NVQ 3, Modern Apprenticeship, MOT Tester, 15+ years experience diagnostic technician
< Last | Next >
  • http://ww2.justanswer.com/uploads/witt0018/2009-02-09_180738_trev2.jpg Trev's Avatar

    Trev

    UK Ford Car Mechanic

    Satisfied Customers:

    271
    NVQ 3, Modern Apprenticeship, MOT Tester, 15+ years experience diagnostic technician
  • http://ww2.justanswer.com/uploads/35/350matt/2012-6-7_182356_matsavatr.64x64.jpg Matt's Avatar

    Matt

    Engineer

    Satisfied Customers:

    1090
    BEng hons Mech engineering, in auto industry 22 years
  • http://ww2.justanswer.com/uploads/FO/fordspec/DSC00877.64x64.JPG neil's Avatar

    neil

    UK Ford Car Mechanic

    Satisfied Customers:

    316
    started as appentice electrician , now specialise in transit
  • http://ww2.justanswer.com/uploads/GazzaR1964/2009-06-03_115816_meingarden.jpg Gary Robinson's Avatar

    Gary Robinson

    UK Ford Car Mechanic

    Satisfied Customers:

    233
    25 years of working on Fords, from Cortina's to Kuga's.
  • http://ww2.justanswer.com/uploads/NA/nabilc/2011-1-24_205715_jap500.64x64.jpg Billy's Avatar

    Billy

    Trainer/Master tech.

    Satisfied Customers:

    76
    Trainer 8+ years, Master tech. 10+ years, SAE member
  • http://ww2.justanswer.com/uploads/TE/techmachine/0601821347169_717372168_8940977_39623330_o.64x64.jpg Ross's Avatar

    Ross

    Mechanic

    Satisfied Customers:

    62
    Automotive Technician
  • http://ww2.justanswer.com/uploads/vidinman/2009-12-28_54613_2_wweks_ago_and_then_this_006.jpg DR CAR's Avatar

    DR CAR

    MOSTLY FORD

    Satisfied Customers:

    44
    39 YEARS GARAGE TRADE MOSTLY DIAGNOSTIC AND FAULT FINDING