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It started with a Misfire, P0304+P0306 P0087 P1CCF
Hello, and good tidings to all who take the time to read this, even more so to the people who take the time to give input.
A few weeks ago now I was driving, and my money light came on as I pulled into work and parked. Started the car up later in the day to move it, check engine light off, okay. I pulled the codes they were P0304-P0306 P0087. At this point, the car was having trouble starting, for the car to start, I had to give it gas and it would turn over.
I took my car to an Independent Mercedes Specialist, they told me after scanning my car and getting the same codes I had already given to them, they determined I need a whole new Fuel Pump, and they wanted $3,000. LOL, I probably would've had them do it if they weren't rude and they didn't charge so much. I won't go into the terrible customer service story here, I just want my car fixed.
Given that I have mechanical knowledge that exceeds that of a layman, I wanted to at least check the basics first. After changing coils and plugs, no difference! I had the car towed to another specialist shop, they performed a compression test and a leak down test. They tell me they found the Injectors to be bad, but I have compression. Oh, and I couldn't even pay them to change the injectors because they told me that they didn't have the ability to code the injectors (FML). These people man, they even had MERCEDES SPECIALIST written on their building in no uncertain terms. I only brought you the car because you advertised yourself as a specialist ( again I won't go into bad service stories rn). I then paid to tow the car home.
Okay! I set out to change the 3 injectors on the offending bank. I'll take the time here to volunteer information to aid in Diagnosis. Between visits to the first and second shops, I put in Liqui-Moly fuel system cleaner. I serviced my throttle body, I noticed a bit of oil behind the gasket. I noticed a good bit of oil underneath the intake Manifold, around the gaskets, I spent 10 minutes here wiping up oil. I checked the ECU for oil, and I noticed only 2-4 connectors with small drops of oil, not that bad. There's a guy on this forum who was pouring oil out of his ECU! Overall, changing the injectors wasn't that bad at all, took about three hours taking my time and being careful. could do it again in 1.5-2 hours. The first time I started my car after changing the injectors, it was misfiring and shaking like **** because I left a position sensor unplugged. I tried to code the Fuel Injectors with ICARSOFT MB V2.0, and it had the option, but the car just wouldn't take it (Maybe because battery voltage was too low?). After that, I had my boy pull up with a snap on scanner and a snap on jump box. the SNAP-ON scan tool didn't have an option, ( to our knowledge) to code the injectors. However, it cleared a lot of codes no problem. After I properly installed everything, I idled the car for about 10 minutes, now up until this point, I have not been able to get my car to reach a steady Idle without misfiring. It was a little shaky at first but it idled smoothly for as long as I left it running. Before changing the Fuel Injectors, the car would make it very clear that it was misfiring, it would shake and sound choppy. The last time I started it, it just went Vroom, and idled, so that was relieving. There's two things that make me worry that the car isn't fixed:
1. CEL is still on, however it's idling fine, I may just need to drive it.
2. While I was idling the car, white smoke that smelt like fuel was coming out. it wasn't very dramatic, I think it's from leaving fuel system cleaner without letting the car run (do you agree or disagree?). My boy was saying it's a bad headgasket, but I told him as I'm telling you all, doubt it's a bad head gasket because I just had a compression test done. As I was idling the car, I never gave it gas, I just let it idle, it didn't get up to operating temperature either.
Well, there it is. I'm at a loss at what to do next. Any and all input is appreciated. Even if you're going to call me a dumb ***, just give an explanation and I'll be thankful for it.
First, you need to get those injectors coded and you need to clear the codes. Second, there are so many values/tests that need to be checked and performed. It looks like a fuel pressure issue which in turn can give you misfires. For the correct diagnosis, you will need Xentry software along with some technical experience in order to get to the bottom of this.
First, you need to get those injectors coded and you need to clear the codes. Second, there are so many values/tests that need to be checked and performed. It looks like a fuel pressure issue which in turn can give you misfires. For the correct diagnosis, you will need Xentry software along with some technical experience in order to get to the bottom of this.
Is Xentry the only tool that can code the injectors? I have access to a Matco 3.0 and and Autel. What's the language it'd be under within the tool, Injection value adaptation?
,
1. CEL is still on, however it's idling fine, I may just need to drive it.
2. While I was idling the car, white smoke that smelt like fuel was coming out. it wasn't very dramatic,
P0304+P0306 P0087 P1CCF
my less than two cents, bad injectors will leak, pooling fuel that burns white and smels accordingly. From a very recent LegitStreetCars episode on a B7 Alpina.
my less than two cents, bad injectors will leak, pooling fuel that burns white and smels accordingly. From a very recent LegitStreetCars episode on a B7 Alpina.
I was thinking that my next step would be injectors on the other side. However I don't know if those injectors are bad or if its from an additive in the tank that sat because I didn't idle/ drive the car
The dude in the video left the car overnight and opened it up in the morning before starting and saw that the cylinders where full of fuel that had leaked o/night. He said that eventually all that fuel will do harm downstream, if the injectors are nor replaced.
again, im just parroting. Not a mechanic, not even a layman.... LOL
You should look into the Low Pressure problem of the High Press fuel pump as indicated by the 2 DTC-s ,P0087 & P1CCF
The ICARSOFT MB V2.0 I am sure has the high pressure data, it is at the engine computer N3/10 module.
You should look into the Low Pressure problem of the High Press fuel pump as indicated by the 2 DTC-s ,P0087 & P1CCF
The ICARSOFT MB V2.0 I am sure has the high pressure data, it is at the engine computer N3/10 module.
Good luck....
LOL, damn bro, why you say good luck like that? Have a little hope.
Thank you though, this is very useful information. Now I know to investigate why fuel pressure could be low during start up. If I'm lucky maybe it's just a bad fuel filter. I'll check the High pressure sensor, if not the high pressure sensor, then I guess I should start with the pump in the tank, because if that's not pumping, the high pressure pump will have nothing to pump.
Please if anyone reading knows better than I do, don't hesitate to call me a dumbass and show me better.
LOL, damn bro, why you say good luck like that? Have a little hope.
Its a well wish my man, nothing negative.
Based on my M276.820 3.0 TT, I am sure your engine/car version would have the same hardware.........
The low pressure fuel pump has sensor too at the filter side ( Left Rear Seat ). The V2.0 can read it too.
If you need to change the HP fuel pump, I suggest the filter in the tank needs to go to....hopefully the low-pressure fuel pump is OK.
The danger of loosing fuel flow to the HP fuel pump is the scoring of the HP fuel pump piston. Gasoline is the cooling and the lubrication too.
For your M276 3.5L engine , 3 fuel cam lobes at the intake camshaft bank 1 ( passenger side for US cars ) I believe and that means at 5,000 RPM that pump does 5,000 / 2 (camshaft RPM ) x 3 lobe = 7,500 strokes.
That is a lot of strokes. My 3.0 TT is even faster with 4 fuel lobes, but maybe the total lift not as high as your 3 lobes.
This video shows the components you need to dismantle to access the HP Pump. Perhaps you best change your oil separator ( PVC) pump while at it too:
BTW..................I am also at the moment studying my car's Low & High Press fuel system to create a predictive schedule for : fuel filter change and HP pump replacement
Too bad our low-press fuel pump controller is the lower end model without duty cycle, unlike some AMG cars.
Ignore the Fluke DMM duty cycle reading, it is not accurate due to 3 phase system our low press fuel pump is.
So above values in the video can be a guide for you for normal operation parameters.
Too bad last Sunday when I took the video, the paid highway was so packed and I can't even do proper 1st - 2nd gear WOT pull, let alone trying for 3rd gear.
Attached HP pump removal/install WIS zip
Last edited by S-Prihadi; Apr 22, 2022 at 10:13 AM.
Surya, I sort of recall the low pressure pump is controlled by frequency, right ?
Can your nice Fluke count the frequency within the pump range, like 500Hz or 1KHz ?
PWM and surely frequency is a component of it : https://automotivetechinfo.com/wp-co...z-Vehicles.pdf
I can't scope non-ground reference 3 phase PWM properly, because I do not have a differential probe.
I can only see the positive voltage and can't see the negative ones.
My Fluke supposedly able to read to 100Khz. But since I can only read 1 of the 3 phases, the Duty Cycle % and Frequency is not accurate for a 3 phase BLDC motor like W212 fuel pump.
I am trying to correlate the VOLTAGE OF FUEL PUMP data from the Xentry/Scanner to Duty Cyle, that was the goal.....but I am not there yet.
If I can read a near maximum duty cycle sat 90% and pressure is say under 5BAR at WOT, that means my fuel filter is kinda clogged. We assume pump is healthy.
I also want to check the location of the low-press fuel pressure sensor at the filter, is that sensor before the filter element or after ?
This sensor position matters a great deal and can worth 0.5 BAR difference at HP fuel pump inlet, excluding head loss at the small hose>>pipe from fuel tank to HP pump.
I want to read manually the pressure at the HP fuel pump intake vs reported pressure by Xentry/Scanner , I now have the fuel pressure gauge kit.
I actually bought new fuel filter from FCP Euro, shipped-landed + import duty, it is still approx US$200 cheaper than MB Indonesia price
My car uses this one : https://www.fcpeuro.com/products/mer...700994#reviews
See my comment as buyer there
I also bought the HP fuel pump too ( arrived) , for back-up sake. https://www.ebay.com/itm/403550117969
99%+ Seller positive reviews from buyers and the actual product I got, I am 99% sure it is genuine. Its a proper company in Germany too. https://www.carloxx.de/
The MB Indonesia price on this HP fuel pump price is crazy, US$1,100 parts only, no labor.
M276 3.5L NA HP fuel pump is different P/N to my 3.0TT and output pipe orientation is different too. Capacity wise probably the same, but the 4 fuel lobes on my 3.0 TT allows overall more flow per minute.
Thank you for this interesting white paper on how our LPFP rpm is controlled like any modern VFD motor.
In machine-shops VFD internally convert the AC mains into a DC supply. Here the control module starts with DC power supplied from the R-SAM. Everything else is similar to VFD's.
The brushless motor rpm is controlled by ramping the frequency of the 3-phase drive. Each phase separated by 120° is a sinusoidal wave form aproximated by a clever PWM.
The article is confusing the Pulse Width Modulation with pump Rpm control!
-- The Rpm is ramped by phase frequency alone.
-- The duty cycle of the pulse modulation is used to chop the DC voltage into a basic sinewave between GND to 12VDC, zero-centered around 6VDC PWM is related to phase angle, not motor Rpm!
Ok practically I think you need a scope to measure the pump frequency by counting on screen period.
A frequency counter will tend to count the 10kHz pulses used for approximation of each 120° phase.
You are interested in the relationship of "Engine Rpm vs. LPFP Pressure". I think there is an existing PID for "LPFP Pressure", right?
What we don't have is "LPFP Frequency vs. Pressure". That is a harder part - The only control we have over pump frequency is by varying the engine demand to vary LPFP pressure supply, right?
SOLUTIONS:
-- either video record all 3 data to match them
-- or measure couple (Frequ./Press.) points at 1000, 2000, 3000 Eng.Rpm to draw a response curve.
zero-crossing sin period (@6VDC center)
I think there is no Pb scoping that to reference chassis GND.
Thanks again for your many interesting research topics. Here, I am most interested in minimizing the electric noises that are disturbing CAN's.
We now know to expect noise generated by:
-- 3 Phase motors: LPFP, Throttle body.
-- 1 Phase fans: Cabin, Radiator.
Last edited by CaliBenzDriver; Apr 23, 2022 at 03:29 PM.
Thank you very kindly Master Surya for this awesome digging.
Scoping circuits is a sure way to gain evidence for practical diagnosis...
Nothing advanced is ever easy - Let me digest the whole article thingy a bit further, it's good solid knowledge: cars + electronics + scopes
++++ Edits: +++++
The interesting aspects developed are:
+ pump Rpm is not equal to current frequency because motor pole count (2 or4) is a multiplying factor.
+ math formula can be applied directly to input channel for display... That way the total pump current can be calculated despite "weird" shape of 3 phases.. cool feature!!
+ The publisher goes on to say the pump being scoped is good. Too bad he could not show us what a bad one looks like with all the clever tools! It's like a shop forman road testing a car before concluding nothing wrong with that new car.. duh!
✌️
Last edited by CaliBenzDriver; Apr 24, 2022 at 03:14 PM.
I wasn't able to completely fix it. But, I was able to figure out where the extra smoke was coming from. I went to check my oil level and it exceeded the dipstick check area! I drained the contaminated oil and filter and turned the car over, smooth idle but it still had unburnt fuel coming from the exhaust. I'm going to take it to the dealer I just want my car to work but I'm wondering wtf is going on. Maybe I need to code my injectors? Does the bluetooth Autel Tool allow you to do that? Could a weak battery be a part of why it's misfiring and throwing codes?
Also! I'm now getting codes for random misfire and misfires on cylinders 2-3 on bank 1. I'm going to get 3 more injectors. Then I'm going to start looking at both fuel pumps. If that doesn't work then the car has to be junk? Like the motor has compression! I don't even want any car anymore I'll take a horse thank you. I had a Honda that had oil dilution problems, now this? Yeah, **** cars.
Small update: I was looking at the sparkplugs that came out of my car and the Mercedes Dealership that was the last to service the spark plugs, put the petrol spark plugs in the car not the Flex Fuel spark plugs. LOL. Woe to anyone who thinks they're superior for paying the stealership
Well, It's fixed, it seems the first shop was right and simply egregiously overcharging. The second shop must have been thinking faulty injector because they had no fuel to flow. I scoured this forum for P1CCF and P0087, because that's what set me apart from other misfire related issues on this website. It seems that those two codes are Mercedes talk for fuel pump time. It went out before 100k miles.
Old fuel pump was taken out under the backseat on the passenger side, I got to the locking ring, knocked it off, replaced the pump, zipped it up, started the car, no more CEL. That's the only thing that turned the CEL off. Coils, spark plugs, injectors.... Speaking of injectors, I didn't even have to code them ****s, here I getting ready to get Xentry, and the car doesn't care the Injectors aren't coded, after I changed the injectors, I didn't put the old ones back in before I changed the low pressure fuel pump. I put in the LPFP, the CEL turned off, no codes about a misfire, besides the stored ones, but it's only been two drive cycles, no codes thrown after 32-35 miles of driving.
Oh the best part, I fixed it with the $90 A-Premium brand LPFP on amazon. I was firing the parts cannon at this point and didn't know if it was going to work, but, lo and behold!
At any rate, it's fixed, without me ever having to set foot in a dealer it's fixed, (Inshallah)
I think injector "coding" not done, if only fuel quantity value, can be offset by the oxygen sensor. Probably you will see more + or - sign for the long term fuel trim . Unless the injector drift too much.
The engine computer can do its own long term correction for the injector firing/opening too, up to a limit. I see my injectors correction value being different say 10,000KM ago than last scanned.
So, what have we learned ? DTC is not always super accurate to describe the CAUSE, but it seems good enough to describe the RESULT or RE-ACTION of the downstream or related hardware........
and we trace the most upstream of the hardware chain....which in your case is fuel supply at the tank.
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