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sean
sean, Technician
Category: Car
Satisfied Customers: 3105
Experience:  UK based Ford Master Technician. Technician since 1984.
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my discovery 3 wont start and shows a fault on the egr valve,

Resolved Question:

my discovery 3 wont start and shows a fault on the egr valve, woud this stopit from starting
Submitted: 3 years ago.
Category: Car
Expert:  sean replied 3 years ago.
Hello, I hope the following assists you.
The EGR valve can stop the engine starting but only if it is stuck in the open position. The symptoms for this would be the engine starts but then stops again straight away as the exhaust gases are drawn back into the engine.
The more likely cause is the P0087 code, this is fuel rail pressure too low.
You need to check that fuel is been delivered to the rail, from memory there is a pump in the fuel tank so make sure this is working OK.. There are other causes of low fuel pressure such as a failed relief valve, failed high pressure pump or injector.
Unfortunately to check the actual rail pressure requires a diagnostic tool that can read live data, this will confirm the rail pressure at cranking.
Even an air leak in the fuel system can cause P0087 so check that there is no air in the system.
I hope this helps.
Best wishes,
Sean.
Customer: replied 3 years ago.

hi sean

thank you for this the injector presures were all reading about the same 1000 psi i think from memory how you check the system for fuel rail presure.

steve

Expert:  sean replied 3 years ago.
Hello again,
I'm not sure how you read the injector pressures as on the 2.7 TDV6 engine the injectors are on common rails that supply the same pressure to each injector, there is a sensor that detects the pressure in the rails and the engine management adjusts the fuel metering valve on the high pressure pump to keep the correct pressure.
1000 PSI is too low, this is only around 68 Bar, at start/idle you should see around 250/300 Bar, the pressure can reach 1600 Bar (23000 PSI) when running this is why you get the P0087 code.
Given the pressures involved the only way to read the rail pressure is using a diagnostic tool that can read live data from the engine management.
Let me know if I can assist further.
Best wishes,
Sean.
Customer: replied 3 years ago.

hi sean

i thought it run out of fuel it went to engin safe mode ant then drove about another 200 meters then stoped and never started again this in turn might be getting starved of fuel?

Expert:  sean replied 3 years ago.
Hello again,
it's certainly a fuel pressure concern stopping the engine starting, not the EGR.
The dropping into safe mode will have been when the engine management couldn't raise the fuel pressure to the desired level, once it drops below a set amount then the engine management will set fuel injection to zero. Unless the engine management sees the target value of 250/300 Bar then it won't enable engine starting.
Start with checking the in tank pump operation and for air leaks, other than this the amount of fuel returned from the injectors needs checking to check if it is an injector, valve or pump fault causing the no pressure fault.
Let me know if you have more questions.
Best wishes,
Sean.
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