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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.
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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: 5 years ago.
Category: UK Car
Expert:  Mike replied 5 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


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