P0087 - Boost cuts and cooling fan goes mental.

Hi All,
Looking for advice re next steps

Have a c3 Picasso 1.6hdi 90 with 126k
Been faultless, 600 miles a week av 60mpg.
Couple of months ago p0087 popped up. Boost cuts and cooling fan goes mental. Restart engine and its all fine again.
MOT and service was due following week so garage cleared eml and said likely to be fuel filter.

Passed MOT and had service but fault popped up every 800 -900 miles , normally accelerating in third up a slight slope.
was recommended a garage & waited 4 weeks for the diag guy to be available.
Said i did not want to chuck silly money at a car that will only get approx 2k trade in.
They called to say leak off test ok and suspected fuel regulator but would need couple of hours labour to remove and test.

Once apart they said the tip of the nozzle was contaminated and would need new, agreed and they went ahead.
Car then failed to start , put old one back on , still non runner. Called on day 4 to say probable contamination in pump so needed a hp pump. Struggling without my car so agreed to a exchange pump.

Got car back and lighter £1350 - 2 days on and P0087 fault returned.
Hacked off and no idea what will resolve this so looking for suggestions pls

Hi ianboylett

ianboylett wrote: ↑Mon May 06, 2019 7:37 pmp0087

P0087 is either a low fuel pressure in the common rail or a faulty sensor reading from the common rail pressure sensor, back to (and including the Engine ECU).

So the testing would be to check the sensor is actually giving the correct reading to determine if the fault is the sensor or the fuel system.

If it turns out to be the fuel system not delivering enough pressure, then take a look for the extra fuel pump located in the fuel tank. This is only fitted to some engines, but when it goes bad, it is often overlooked. So checking if you have one may be useful to check/test etc.

The other issue can be a correct sensor and good pressure generation but its lost by a leaking injector.

Once apart they said the tip of the nozzle was contaminated and would need new, agreed and they went ahead.
Car then failed to start , put old one back on , still non runner. Called on day 4 to say probable contamination in pump so needed a hp pump. Struggling without my car so agreed to a exchange pump.

Since you have had most of the top possibles checked or changed, there is the low pressure pump to check for.

fault popped up every 800 -900 miles , normally accelerating in third up a slight slope.

having discovered a pattern is useful, but I haven't worked out how to use it yet.

Thanks for the reply, dealer told me it was just a sender unit in the tank.
The only pump is the HP pump.

ianboylett wrote: ↑Mon May 06, 2019 8:17 pm Thanks for the reply, dealer told me it was just a sender unit in the tank.
The only pump is the HP pump.

Without actually getting my hands on the engine, it leaves the pressure sensor itself with it's associated wiring and ECU connection.

Usually the fault is the HP pump side of things and this has been changed, a leak off test would show it as an injector.

So can the common rail sensor be tested? or just change the rail with another one? Inspect the plug at both ends etc... Get some live data on how the pump is performing (or detected to be performing etc)

The only niggle that I have to get to grips with is the patten you identified. I am sure this can help, but I still don't know how....