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 Your Own Question

Mike, UK Car Mechanic
Category: UK Car
Satisfied Customers: 39198
Experience:  Hi, I am a Car/ vehicle technician of 34 years. 29of -running my own repair/diagnostic business.
Type Your UK Car Question Here...
Mike is online now
A new question is answered every 9 seconds

I have a vivaro 03 plate..high pressure pump

Customer Question

Hi there, i have a vivaro 03 plate. it will not start! I have changed the high pressure pump and solienoid. I have disconnected the feed pipe to the common rail and whilst cranking over there is no sign of fuel (not a drop). i have tested the in tank bosch pump with a 12volt feed and it runs fine sending fuel around the systerm back to the tank via the return pipework. This pump only runs for about 1 second when powered buy the ignition, it normally runs for longer. is this pump controlled buy the common rail pressure senser or a relay. if controlled buy a relay could you tell me where i would find it. Many thanks Tom the plumber, Isle of Mull
Submitted: 4 years ago.
Category: UK Car
Expert:  Mike replied 4 years ago.
Hello and Welcome to justanswer...

The first thing to note is that these systems should never be opened when the engine is running - or even cranking as pressure is extremely high and can cause fatal do be careful there...

The first thing to check -very carefully - is the wiring to the fuel rail - pump etc - as they have been known to break wires in the loom..

As it is of course you have a lack of pressure problem so the question is why.. The in tank pump on these used to cause problems. The fuel pump relay - for that pump, is in the engine bay fuse/ relay box - and is brown in colour.

This could be your problem and is certainly worth investigating but after that - if replacing that or even bypassing it to test doesn't cure this for you - then you are going to need to have diagnostic equipment plugged into the OBD diagnostic socket to trace the fault.
These had issues with Ecu software causing fuel delivery / pump problems - and that can only be diagnosed using proper plug in equipment Im afraid..

I do actually suspect strongly that you have either a pump or an injector fault. These systems rely on pressure - they have to build a certain pressure ( very high as mentioned ) and if even one injector goes faulty staying open which is common - it cant build the pressure and therefore wont start. Before that of course is the injection pump and too , these do fail...

So Im afraid you are going to need proper plug in test equipment on this to trace this down properly. That equipment tests the pressure too this way as its electronically controlled and will find any faults there as well as pump or other causes..

So you can try the relay as above but after that you really are into needing it testing with equipment as above to find the cause of your non start problems here Im afraid.. There is just only so much you can do on these systems these days without equipment sadly. It needs a Fcr - fault code test at least ..and then go from there based on the results of that...

I'm very pleased to have helped you - but do ask me if you need anything more..

Kind Rgds, MIKE


  • >>>>>>>>>Please don't forget ....Please press the ACCEPT button if you are happy with my answer/advice given - as that's how I get paid for my time, knowledge and expertise given. Thank you.

Feedback and any Bonuses are always appreciated too. Thank 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... seen a spike since October in legal questions from readers about layoffs, unemployment and severance.
Web sites like
...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
< Previous | 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:

  • Marty


    European Car Expert

    Satisfied Customers:

    ASE & Bosch Certified Master Tech. Over 30 years experience.
< Last | Next >
  • Marty's Avatar


    European Car Expert

    Satisfied Customers:

    ASE & Bosch Certified Master Tech. Over 30 years experience.
  • Greg's Avatar


    Shop Owner

    Satisfied Customers:

    17 years Shop Owner /Technician. 27 years experience,
  • Richard's Avatar


    UK Car Mechanic

    Satisfied Customers:

    12 years as a technician at a Ford and Jaguar dealer Ford and Jaguar factory certified
  • Matt's Avatar


    Mechanical Engineer

    Satisfied Customers:

    BEng hons Mech engineering, in auto industry 22 years
  • Billy's Avatar


    Trainer/Master tech.

    Satisfied Customers:

    Trainer - master tech., SAE member
  • Trevor's Avatar


    UK Car Mechanic

    Satisfied Customers:

    NVQ 3, Modern Apprenticeship, MOT Tester, 15+ years experience diagnostic technician
  • Rob's Avatar


    UK Car Mechanic

    Satisfied Customers:

    city and guilds level 1 2and 3. mot tester , 28 years experience set up training college in afghanistan