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Lately my car had shut down its engine mutiple times while I was driving. Before shutting down it felt like I took of my feet from the gas pedal and then pressed it again althrough I always was on full throttle. I could restart it immediately after it shut down.


I then logged some parameters of the car using OBD2. There I noticed that the Fuel Rail Pressure dropped multiple times (see first diagramm). At the last drop the engine shut down (didn't react to adding gas and rpm dropped to zero).

After the shutdown of the engine I find the errorcode P0087 in my cars systemlog.

In idle mode the pressure is (nearly) stable as shown in the second diagramm. Be aware that the scale isn't the same as on the first diagramm!

diagramm Fuel Rail Pressure

enter image description here


What is the cause of this?

The Car is a Ford Focus Tunier 1.6 tcdi diesel 109 PS constructed in 2006 and it has about 145.000km / 90100 miles

Futher information (mentioned in comments)

  • Last full service at about 130.000km / 80880miles
  • Fuel filter changed at about 114000km / 70836miles

Solution

I followed the list provided by GdD. The replacement of the fuel-filter solved the problem. The engine works again and the error code doesn't appear anymore

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  • When was the vehicle last subject to a full service? Jul 12, 2018 at 11:24
  • About a year ago at 130.000km/80880miles Jul 12, 2018 at 11:50
  • Could be worth swapping out the fuel filter just to be sure. It’s the cheapest and most easily replaced part that could cause this behaviour. May be worth checking the condition of the fuel supply lines too. Jul 12, 2018 at 11:54
  • That also was my first thougt. It was changed at 114000km but i already ordered a new one which should arrive tomorrow Jul 12, 2018 at 12:01
  • Could you post a graph of the rail pressure while idling? How does the car behave then?
    – Martin
    Jul 12, 2018 at 15:53

1 Answer 1

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If the fuel rail pressure is dropping then either something is obstructing fuel flow intermittently, or your fuel pump is having issues. I'd start with the cheaper things to look at:

  • Fuel cap: As fuel is sucked out of your tank air must go in to replace it, otherwise you get a lack of fuel flow. Generally the fuel cap is responsible for this, if it gets sticky then the valve in it may not be operating as it should. Try cleaning it first, replacements are cheap too
  • Fuel filter: I'd usually expect a clogged fuel filter to be a constant rather than intermittent problem, but it's certainly easy and cheap to replace
  • Fuel contamination: it could be you got a bad tank at your last fill-up, try a different station
  • Fuel lines: If fuel lines are getting impeded somehow you could have intermittent dropoffs of pressure
  • Fuel pump: If your fuel pump starts to act you can get this symptom, but I'd check the other things first
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  • Good list. I'd highly suspect the pump valve, as the symptoms match.
    – Martin
    Jul 12, 2018 at 15:49

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