michaelm352

So the story goes like this, 2014 E350, 197k. Just returned from a trip from Florida to Tennesee, was gone a week and the car ran like a top. FIlled with fuel about 30 miles from home,, then the car sat for a day as we have other vehicles. Monday rolls around and when starting cold, it was running very rough and the CEL flashed then went solid. I checked codes, P2540 indicating an issue with the fuel low pressure sensor along with mis-fire on 1-2 and 3. Cleared the codes, car ran fine. Drove about 200 miles for work, no issues. Next morning same issue, rough on start, cleared same codes, ran fine again all day. Wednesday it started rough but I could not get them to clear (didnt think to shut the engine off and turn on the ignition), so I limped it to the local independent whom I had used before to do a fuel pump about 30k miles ago. He checks it out and says cylender #2 has zero compression, needs a motor. I had the car towed back home and went back at it, today it had a mis fire on 2 current and a code about the coil being open circuit. Pulled the airlceaner, low and behold, the electircal connector was not fully connected. Slid it in and cleared codes, now i am getting P030085, P030185, P030285, P030385 indicating all left bank cylenders are misfiring. After warming up a few minutes, it seams to clear and smooth out, But the codes come right back after resetting...Im simply wondering why the car was fine until one morning this all started. Im also wondering how i was able to clear codes and drive the car without issue for two more days before they codes refused to clear, and lastly, what could cause a mis-fire on only one bank without throwing any other codes? A mystery to be sure. I am going to look for and order the tools to do compression and leakdown just to verify that is or is not an issue.

Thanks for any input!
Michael A
'14 E350

Raj1471

My guess would be a fuel delivery problem with the first code being thrown on your vehicle. Start with fuel delivery and ignition...were coil and plugs ever serviced during your ownership? Possible fuel contamination issue maybe...just spitballing here. Check on YT with P2540 code...all pointing to fuel pressure sender under rear seat.

S-Prihadi

Can I ask some :

"to do a fuel pump about 30k miles ago"
So you have replaced your low pressure in-tank fuel pump at 197K - 30K = 167K miles, and you never replaced the in-tank fuel filter ?
If that is true, you best immediately replace your fuel filter because when you cut it open, you will find it is very badly clogged.

Sometimes I laugh but with sadness, if any techy or DIY person can believe a normal non-defective , non-stressed Low Pressure fuel pump in the tank can be shorter lived
than the LP fuel filter useable life

Even say the most ultra conservative style driver capable of doing 30 US-MPG or 12.75 KM per liter average , which means 197,000 miles divided by 30 MPG is = 6,566 US gallons or 24,821 liters
of fuel has been filtered by the tiny tiny in-tank fuel filter and expect the fuel filter to be still able to do sufficient fuel flow all the way to WOT in 1st and 2nd gear while achieving at least 5 BAR read at LP fuel pressure sensor, that is a weed generated illusion.

Unless one uses 2 micron pre-filter at each and every fuel re-fill, 6,500 gallons of fuel has enough allowed contamination/dirt standard to overwhelm the maximum
10-15 grams dirt holding capability of our in-tank LP fuel filter by much if not 300%.

One more thing to observe.
Our W212 normal gasoline fuel tank ( I do not know anything about flex fluel capable fuel tank ) is a weird 2 tanks in 1, so to speak. LEFT and RIGHT saddle or zone.
This 2 zones can only parallel themselves when fuel at about 75% or more. This upward depression of the fuel tank middle zone is for allowance of main propeller drive shaft.
The fuel filter ( at LEFT side tank ) has bleed back mechanism they called venturi or jet pump , using stupid low grade clear plastic hose to transfer back
fuel from LEFT side of tank to RIGHT side of tank where the fuel pump it located in a sort of a"bowl".
This bowl is to make sure fuel will submerge the fuel pump for cooling and ease of having enough fuel to not have pump sucking air when fuel level is low.

Now, aside from bad habit of often running tank dry or lower than 1/4 fuel level and exposing fuel pump to less cooling by NO fuel submersion ( fuel pump live shortened this way ),
that stupid clear hose which its duty is to send back fuel from RIGHT side tank to LEFT side tank, will age and get brittle overtime. When this clear plastic hose get brittle, it can also
leak fuel at LEFT side tank and reduce the overall fuel volume delivery to the RIGHT side tank aka fuel pump.

To know a good working condition of fuel transfer between LEFT to RIGHT side tank, when we lift up both the fuel filter and fuel pump to see fuel level visually,
the RIGHT side fuel tank will always have higher fuel level than the LEFT one ( fuel filter side ). This is best done at 1/3 fuel gauge level and no higher.

How does one accelerate the death of a LP fuel pump ?
The LP fuel pressure sensor at the LP fuel filter external body is located at the CLEAN side of the fuel filter element.
So the N118 fuel pump controller has a target of approx 5.8 to 6 BAR to achieve if fuel filter is a 100% clean, those are CLEAN side pressure or output of
LP fuel filter.

The more dirt the LP fuel filter paper element has collected on/in its media, the higher the head pressure at the DIRTY or input side of the LP fuel filter, to achieve the proper
pressure at the CLEAN side of the filter. This is the differential pressure or pressure drop a dirty fuel filter paper element created.
The N118 fuel pump controller does not know a dirty fuel filter element as it only has 1 pressure sensor, which is the one at the CLEAN side of the fuel filter.
So N118 will send more current/watts to the LP fuel pump to achieve the target pressure and overtime the LP fuel pump will be damaged from over-worked,
when and if the fuel filter is not replaced properly in-time. This is how one can have a LP fuel pump shorter lived than a fuel filter clogged life.
Because one never bother to measure pressure drop at fuel filter CLEAN side and relying on DTC of low fuel pressure or waiting for driveability problem.

A low cost LP fuel filter assy which gets you new fuel level sensor, new LP fuel pressure sensor + all those low grade clear hose....basically all new,
then becomes an expensive 3 phase fuel pump replacement. 3 phase LPFP is for some newer E350 M276.

If Uncle Murphy does not like our poor maintenance procedure, the next job will be the HP fuel pump mini sliding piston rod getting scored.
Anytime one get misfire due to fuel starvation, the HP fuel pump takes a hit too, bit by bit from either dirty fuel escaping the media or by lack of fuel.
Fuel is the lubrication for the 200 BAR Bosch HP fuel pump internals.

So, before you do anything, if the existing fuel filter in the tank is original to the car of 197K miles, please replace it.

You then tear open the fuel filter element for autopsy and share with us.

CaliBenzDriver

> FL high humidity....
in addition to all the above knowledge pointing us towards tank:

while replacing filter assembly you'll want to take this opportunity to pump out water condensate from both sides of your saddle tank.

Use a cheap inspection snake camera to look inside your tank partitions for tank condition and evidence of water condensates.


> Data ruled injection:
Use your scanner DATA to diagnose fuel delivery.
This will help you focus on what's bugging your engine by priority. ie. ignore "Cyl.2 low compression" when the whole Bank.1 is concerned.

- What HPFP look like ??
- Do you spot tank LPFP struggling ??
- What are LTFT the long-term fuel trims ??

The above data will give you confidence in the repair status: compare Before/After measures.
The ECU faults only point to bare minimum legal conditions.... do not rely on codes to be self-sufficient diagnostics.

michaelm352

The pump was replaced professionally along with the filter.

Now I have to ask, why would a bad filter in the tank cause the engine to only mis-fire on one bank? Would not a fuel starvation problem cause mis-fire throughout the engine?

The issue is consistant on 1-2-3.

Siegmann

You probably have a leaky injector on bank 1. That would explain the misfires and the fuel pressure code (an injector that won't close makes it difficult for the pumps to generate their commanded pressure). I would expect to find negative fuel trims (which causes the other 2 cylinders to run lean in an effort to reach target mixture, which is read by 1 sensor for all 3 cylinders per bank). Whichever cylinder has the highest misfire count is likely the one with the problem. Although if your injectors are original I'd replace all of them as they are critical for longevity in a DI engine.

Senecat

200k? Nice.

Replace injectors, coils, and plugs and have a nice day.

S-Prihadi

Good that the fuel filter is only 30K miles today.

I shall give you my guess-timate :
Cylinder 1, 2 and 3 are at BANK 1, RIGHT side bank or passenger side for US LHD car.
When the fuel filter was replaced it could already harbor enough dirt on its clean side.
The dirt then migrate to the output hose of the fuel filter and to the engine bay and to HP fuel pump.
The HP fuel pump is at Bank 1 too, the output pipe of HP fuel pump is shorter towards Bank 1 and much longer towards Bank 2, see below for M276 3.5NA
B1 = Bank 1 ...............B2 = Bank 2



Now if the dirt is at the entry point of Bank 1, it can cause flow restriction to the injector cylinder 1 2 and 3 and you can get a misfire at those 3 cylinders ONLY, misfire from being TOO LEAN.
To have injectors 1, 2 and 3 failed at the same time is very rare.

As to why sometimes the engine can run normal and then misfire again within a short period of time is usually because :
The dirt or material clogging the fuel rail of Bank 1 could be moving a bit here and there and at times allow enough fuel for non agressive driving.
This clog finally got so bad, you then have the permanent misfire code.

There was a similar case to my guesstimate of your misfire condition, but the contamination material was pushed deep enough to Cylinder 1 only and its size is not that big to cause misfire as bad as yours. See post no #204
https://mbworld.org/forums/e-class-w...ml#post8803192

Use your scanner to see HP fuel rail pressure, which too bad is located at the Bank 2 rail and not Bank 1, but it can at least indicate HP fuel pump pressure
to at least verify HP fuel pump pressure is good. 120BAR minimum at idle is to be expected.

Have fun troubleshooting

S-Prihadi

There is another item, but not fuel related which also serves cylinder 1, 2 and 3.
Fuse 23 which powers COP 1, 2 and 3 and some sensors.

Fuse 23 network of consumers has a splice called Z738z1.
If power is bad/low from fuse 23, you can also get misfire from COPs, due to lack of power for ignition.
Do a voltage measurement under load at the grey+black 14 pin connector called X26 no 1 connector, pin 5 and at either one of the COP connector pin 3.
Attached wiring schematic of M276 3.5NA

Go to that linked post Misfire Nighmare to find where is X26 connector no1 is on your engine.

CaliBenzDriver

Bank1 is where the worned out intake camshaft phaser lock-pin hammers the tone wheel loose.

This royaly screws up Bank1 timings until ECU realizes tics are mismatched beyond tolerances.

The fact this does not happen to Bank2 at first, suggest it is related to marginal oil pressure consistent mainly with city driving, ECO S/S plus reduced oil pressure...


To help prioritize your diagnosis, scrutinize:
fuel pressures
fuel trims
VVT timings
--

michaelm352

Great suggestion and would make sense if #2 is flooding with fuel, would cause wash out and a possible inaccurate compression reading. I am heading out to watch the live data and see if i can determine if this is indeed the case. Very plausable idea though, thanks!

michaelm352

Coils and plugs are less than 20k since done. Injectors are next

michaelm352

Updates: I have other cars and life has gotten in the way of taking care of my problem, but I am still on task. I sent the car to another shop awhile back who did the same blind test and said number one had no compression, which confirms my suspicion, it is not a compression issue. I towed it back home and it sat awhile. I ordered and replaced the injectors and seals, and after replacing them the only code I am getting is the mis-fire on cylinders 1,2,3. The other codes are gone and do not return. Still running rough but much better than before. I can actually drive the car. I let it sit some time after doing the injectors and because other issues requred my time on the weekends but today I had time to pull things apart again, so I did. Off came the fuel rails, all clean as a whistle, no blockage at all. They were full of fuel and passed air easily. Borascope into the cylinders showed no physical damage visable. Replaced all intake and injector seals again just for good measure. Pulled the fuel pump covers and siphoned a ton of fuel from the tank, crystal clear as well. Inspecting both sides, the hoses are in tact and the tank is spotless inside, no trash or contaminants at all. almost too clean for its age. All back together, random mis-fire on 1,2,3. I am heading out to see if I can catch some live data based on the above suggestions, so stay tuned.

Siegmann

Did you code the new injectors to the computer? Each injector has a 5-character calibration code laser marked on it.

S-Prihadi

Xentry has Compression Test feature which show you pistons speed, all 6 pistons.
Where compression is lost or much lower, that piston/ will speed up faster than healthy cylinders. Test using that and see what values you get.
Read here : https://mbworld.org/forums/e-class-w...operation.html

JettaRed

iTrader: (1)

I do wonder how a rough running engine can smooth out if there is no compression in one of it's cylinders. You might miss it on a V12, but certainly not a V6. I have a 2000 Ford F150 with a V8, which are known to blow the spark plugs out of the head because of an engineering design flaw, and when one of those goes, you definitely know it. AND it don't repair itself.

@michaelm352 , one mechanic said cylinder 2 had no compression and another said cylinder 1 had no compression. I'm beginning to think you pick the wrong mechanics.


@S-Prihadi who are the weed generated?. Boomers?

michaelm352

The shop I purchased them from said they were pre-tested and a matched set "ready to go in". Is there more that I need to do? Eiether way, the issue remains the same before and after as far as the mis-fire goes, no change what so ever. The other codes are gone.

michaelm352

This is the test the two shops used to determine the engine has low compression, first on #2, then the second shop said #1. Both are know local MB shops with certified techs and all the proper equipment, but I believe in both cases, they did not listen to the customer and the circumstances, just put on the tester and decided an engine job was at bay 1. Not buying it, the car was on again / off again for two days, now it is randomly misfireing across the three cylinders, not all the time, not any one cylinder all the time.
I have a new code as of last night, intake leak on bank 1 after driving the car about 2 miles..

JettaRed

iTrader: (1)

What are you talking about? Fuel injectors?

JettaRed

iTrader: (1)

Has the car overheated? It's beginning to sound like a warped or cracked cylinder head.

How low is low? Compression too low will not allow the fuel to ignite. But, as you crank to start the engine and it heats up, the defect could close or seal tighter, increasing compression pressure, and allowing the car to run a bit. Then, as it cools down, the problems return.

A quick and cheap way to test for a bad cylinder head and/or gasket is to use a block tester that measures any exhaust gases that have gotten into the coolant. You want to rule this out. Otherwise, you will be chasing gremlins.

michaelm352

yes, injectors

Siegmann

They need to be coded to the car to correct fuel trims. This can be done with Xentry or iCarsoft MB 3.0. It may further smooth out your engine.

2013 E350

I think I'd start to suspect a problem with the engine ECU.

TheBenzIsOne

I'm trying to send you a pm

TheBenzIsOne

I ended up purchasing this vehicle from Michael and am now trying to figure it out. Ive swapped intake manifold gaskets, battery, coils, plugs, cyl #2 injector and no resolve. I'm starting to think that CaliBenzDriver may be correct. I too did a compression check and cyl 2 was low while cyl 1 was around 200. Then on a recheck cyl 1 had zero compression. Thanks in advance for any input.