W204 C220 CDI Auto - P0087 Fuel Rail/System Pressure too low - how to diagnose?

[PatrickHogan]

I am having an issue with our 2014 W204 C220 CDi Auto that has covered 169k miles.
A few days ago, under heavy acceleration uphill, the car lost power instanteneously and coasted to a stop & stall.
Engine management light came on.
Tried to restart, starter was turning but the car would not fire.
Turned it off for a few minutes and it eventually restarted. Engine management light stayed on.
Tank had around a third of a tank of diesel.
Managed to get the short distance home and plugged in my diagnostic to read the following error:

P0087 Fuel Rail/System Pressure - too low

I cleared the code and the engine management light extinguished.

Yesterday, joining a motorway, under moderate acceleration, the engine management light came back on - this time without loss of power.
Scanning the code gave the same DTC - P0087 Fuel Rail/System Pressure - too low

As long as heavy acceleration is avoided, the car is running normally.

From reading around the forums, it seems like it could be any one of:
1. Bad/blocked diesel filter?
2. Bad Fuel pressure sensor (where is this located? on the fuel rail in the engine bay, or on top of the tank under the back seat?)
3. Bad High pressure fuel pump?
4. A bad injector?
5. Bad hose/other?

What is the procedure in diagnosing this issue?

Other information.
The EML seems to go off by itself after 3 "good" ingition cycles.
Diesel filter was replaced 15 months /11,000 miles ago. [MANN-FILTER WK 820/17] Is it worth replacing this first?

Thanks in advance.

 

[Dodipops]

Yes for the cost of a filter it’s the first thing to try.

The diagnosis would be a low pressure test with a gauge to make sure that doesn’t drop under acceleration, that tests in tank fuel pump and lines/filter blocked.

Then you would have to do an injector leak off test and fuel pump pressure regulator blank to test the pump and regulator

All these tests require a fair amount of specialist equipment.

So maybe worth a few hours labour at reputable garage or diesel specialist if it’s not the fuel filter.

 

[sameti22]

How did you sort this out please i got the same problem?!?

 

[sameti22]

I am having an issue with our 2014 W204 C220 CDi Auto that has covered 169k miles.
A few days ago, under heavy acceleration uphill, the car lost power instanteneously and coasted to a stop & stall.
Engine management light came on.
Tried to restart, starter was turning but the car would not fire.
Turned it off for a few minutes and it eventually restarted. Engine management light stayed on.
Tank had around a third of a tank of diesel.
Managed to get the short distance home and plugged in my diagnostic to read the following error:

P0087 Fuel Rail/System Pressure - too low

I cleared the code and the engine management light extinguished.

Yesterday, joining a motorway, under moderate acceleration, the engine management light came back on - this time without loss of power.
Scanning the code gave the same DTC - P0087 Fuel Rail/System Pressure - too low

As long as heavy acceleration is avoided, the car is running normally.

From reading around the forums, it seems like it could be any one of:
1. Bad/blocked diesel filter?
2. Bad Fuel pressure sensor (where is this located? on the fuel rail in the engine bay, or on top of the tank under the back seat?)
3. Bad High pressure fuel pump?
4. A bad injector?
5. Bad hose/other?

What is the procedure in diagnosing this issue?

Other information.
The EML seems to go off by itself after 3 "good" ingition cycles.
Diesel filter was replaced 15 months /11,000 miles ago. [MANN-FILTER WK 820/17] Is it worth replacing this first?

How did you fix itt ??

 

[PatrickHogan]

So just an update on this issue.
I finally booked the car in with my Mercedes specialist.

He carried out check on the fuel pumps and read the live data for pressures and so on.
Everything seemed ok.
Then he carried out an injector leak off test.
Injector 1 (front of engine) was really bad.
This was replaced and the car is running well again now.

I hope this helps you with your problem.
@Dodipops advice in post #2 above seems like sound advice.

PH