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Yoka,
Something is probably defective at either your High Pressure fuel pump or the low pressure fuel pump at tank or its filter ( source ).
The delay u mentioned for high pressure fuel pump pressure to hit 150 bar is way too slow........
If you read this thread carefully, you would have spotted how a healthy High Pressure fuel pump should behave within 2 seconds after engine start.....
Below is 1 second per data point
I know how it should working, question is why is mine working wrong. Like I said changed for brand new it's exactly the same....
Sometimes I start the engine and pressure seems to be perfect (150Bar), it does it maybe 2-3 times every 50 tries...
I did not see you mentioned changing low pressure fuel pump and filter at the tank.
The above 2 items are the primary source, the HP pump is a booster. Filter will be dirty overtime.
So if source is little/weak/slow/restrictive, your HP side will not work well too.
The intermediate potential problem is the fuel hose, from tank+filter+pump to HP pump.
Either you measure the fuel quantity output or measure the fuel pressure of this low pressure hose, there is a valve+fitting at the engine before it enter HP pump.
Doing both will be better.
This is assuming there is nothing else wrong on the command side for the HP pump, which is the electronic/software/electrical side of things.
If I were you, I will always troubleshoot fuel system at ground zero, its very beginning, its starting point.....
I did not see you mentioned changing low pressure fuel pump and filter at the tank.
The above 2 items are the primary source, the HP pump is a booster. Filter will be dirty overtime.
So if source is little/weak/slow/restrictive, your HP side will not work well too.
The intermediate potential problem is the fuel hose, from tank+filter+pump to HP pump.
Either you measure the fuel quantity output or measure the fuel pressure of this low pressure hose, there is a valve+fitting at the engine before it enter HP pump.
Doing both will be better.
This is assuming there is nothing else wrong on the command side for the HP pump, which is the electronic/software/electrical side of things.
If I were you, I will always troubleshoot fuel system at ground zero, its very beginning, its starting point.....
I did not change low pressure fuel pump.
As you said, need to begin from ground zero, posted only cause hoped someone had exactly the same story and would say/write something like " I've bought 10g of uranium, put into place etc..."
Thank you for reply, think it is going to pushed me a bit into fuel tank direction, till now neglected by me cause readings from Control Unit of low pressure pump seems to be ok..
The problem I see often today is, one relying on scanner too much, as such the core of the "information" is being missed and the typical old & proven style troubleshooting thrown out of the window. THE FUEL PRESSURE IN THE SYSTEM IS TOO LOW
How many pressure areas are there in the fuel delivery system ? 2
1 low press and 1 high press
Which is more upstream ? Low press
Can HP pump deliver more fuel quantity than what it receives from low press circuit? No
The OP of this thread had done his troubleshooting up to verifying low press pump's pressure ( using mechanical gauge) up to its end point, which is before fuel enter the HP pump.
The only thing not conducted was, fuel quantity check/verification.
Fuel quantity per minute out of the pump is an additional health check good guarantee, on top of the pressure.
Since OP is not using original pump, I can't say that his liters per minute capacity of the pump at X pressure is as good or equal or better or worse to/than MB original pump.
If one deals with water pumps often, one would know that one need to see the pump curve if he wants to be sure a 100% and a flow meter is the last MUST HAVE.
Lets use 220 grams per KwH of fuel as M276 3.5L fuel burn. Specific gravity of gasoline, let's use 0.75 metric.
So 293 cc per KwH x 225Kw = 70 liters per hour full power.
Low Press Pump capacity , give it 175% or 122.5 liter per hour or 2.04 liters per minute ... would be something minimum I want to see pump out by low press fuel hose near engine block
into a measuring container.
I hope your scanner can command fuel pump actuation, otherwise its a 3 phase PWM controlled and you can't simply manually power it like a common +12V and -12V wired pump.
I encountered a similar issue and wanted to offer some advice without you having to spend unnecessarily. Consider checking the following:
1. Your fuel filter may need replacement.
2. Consider replacing the Z530A fuel control valve.
Too much knowledge in here, I must ask in the P0087 thread.
2013 GLK 350 140k.
I initially got a check engine light due to a P008A code only.
I changed the fuel filter, code didn't go away.
Bought a gauge,, seen low side fuel pressure was bouncing around between 30 and 60, under specs.
I changed the fuel pump, code didn't go away, and THIS is when I got the P0087, but only "Confirmed", it's never gone Permanent and set off the CEL. Fuel pressure a sold 65 psi now.
Then I changed the fuel pressure / temp sensor and haven't seen P008A since.
However, P0087 remains in the background, confirmed but not permanent. Not setting off the CEL, or able to pass inspection.
I've got a blue driver scanner and I can watch fuel rail pressure between 2150 and 2950 which is in spec and I don't see anything permanently wild with the fuel trim. Usually always under 5%. I watch it frequently short trips around town sometimes short-term will bounce to 10 or 11%. Not even trip. Not long term.
I've driven enough miles I feel like the code should go away but it's been there ever since the new fuel pump went in.
zakgt; thanks for the input, always like to see good tips for issues. On the other hand I hate to see threads just stop without a solution or follow up. I wonder if the OP gave up, or fixed it and never came back?
GLK; I suppose I would clear the code and see what happens. It's possible BlueDriver cant do it, so maybe see if that's a yes or no. If you can clear and it comes back, I'd trend that pressure every moment the eng is on to see if you can spot a dip. That means before you start it too.
The fuel trims probably wont show anything because the injection calculation includes pressure, so instant correct adjustment.
zakgt; thanks for the input, always like to see good tips for issues. On the other hand I hate to see threads just stop without a solution or follow up. I wonder if the OP gave up, or fixed it and never came back?
GLK; I suppose I would clear the code and see what happens. It's possible BlueDriver cant do it, so maybe see if that's a yes or no. If you can clear and it comes back, I'd trend that pressure every moment the eng is on to see if you can spot a dip. That means before you start it too.
The fuel trims probably wont show anything because the injection calculation includes pressure, so instant correct adjustment.
Blue driver only connects after startup so I can't watch it go from 0 unfortunately. And it won't clear this code I tried.
I've had the high pressure fuel pump in my hand twice, once when doing vvts, and again for a PCV valve wishing I had done it the first time in there, and I didn't notice any wear, and obviously got it back in correctly twice, and that was 3,000 miles ago. I did leave the foam heat shield off that things ridiculous. I guess it's my next dart if it don't go away. I just find it really strange that the code never appeared until after I replaced the low pressure fuel pump which is now working perfectly.
I adon't understand why it would only present as confirmed, never permanent, especially if you're not going to pass smog lol
I just recently had this message come up on my 2013 C300. The car died after coming off of high idle. Car refused to start again. I got it going the next day to limp it home. Where it died again. After first changing the sensor to no avail we needed to dig deeper. We isolated the left and right rails and fired up the pump. We discovered that there was fuel leaking around the top of one of the injectors. We tried to replace the seal at the top of the injector to no avail. Still leaking. Upon further inspection it appears that the top of the injector is pitted. This allows fuel to bypass the injector and it gets captured by the return side of the rail and gets dumped into the crankcase. The engine needs 10 bar to start and we could only measure 5. The injectors are about $900 from the dealer and $700 from Bosch. Since we had a second injector that was starting to pit we replaced both injectors and the fuel rail along with all new seals. Also, needed to reprogram the computer to tell it that we replaced 2 injectors. Each injector is numbered and is configurable in the computer for it's position. One tell tale sign is that the crankcase was full of fuel. On the bright side there is no more carbon in the engine.
Looking for any assistance to diagnose a CEL P0087 low Fuel Rail Pressure on E550 M278 with 90K. Owed the car since 20K and still love it. Still get great mileage and have not had any other issues starts right up.
Car will throw the code on heavy acceleration (put the pedal to the floor) turbos kick in pulls hard up to 5000RPM and she then goes into limp mode. If shut down and restarted runs fine. if babied will run fine for quite a while
How can I check the Fuel Pressure sensor on the fuel rail?
Where can I put a T in to check fuel pressure I have not found a place to tap in?
I replaced the following due to mileage, age and low pressure CEL P2540 hoping it would correct the issue
The Right and Left Fuel Pump Assembly - Mercedes-Benz (218-470-00-94) and
the left Fuel Sender Unit - Mercedes-Benz (218-470-09-94)
If fuel high pressure regulator fails would it begin to throw off the engine’s air fuel ratio, which can lead to engine misfires?
i had same issue on my ml om642 aswell as on my ford focus 2016. before anything pls check on the lelctrovalve of the turbocharger aswell as the vacuum pipes. low costs and i guarantee that if u replace the valves of turbo (should be 2 ) ur problem will dissapear.
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