B34chBum

@DIY_garage - the injectors are known to the ECU, each one is registered/coded into memory at installation.
If you had them out together and put them into motor in different order it would confuse things.

I've not done this but I think the coding numbers used are on the injector bodies, from reading elsewhere / other posts.
Others could please chime in.

arto_wa

I have not done it either, but did some homework on this subject couple of years ago after my 2008 W211 had an error code after a cold start in about 0F temperature.
Once back home I plugged in to Star diagnosis and cleared away the error code and it has never been back since.


Here is what I just read regarding injector identifying in ECU:




DIY garage:
I think lot more homework is required, but I am certain we have members here who can help!

DIY garage

So I finally managed to start my 09 ML320 bluetec. As mentioned I have taken out all 6 injectors and disassembled each one to clean from carbon buildup. The suv had rough idle when started cold in the morning, after warming up ran just fine each time when started. The suv has been barely driven for last 2 years by previous owner. Since all new injectors were to cost me $6000 plus labour (yes $1000 each, one only understands why when completes a disassembly, some very fine German engineering there. Things to remember are location of each particular injector, so mark them whatever makes sense to you, when injector is out scribe a sharp line along the injector prior to disassembly of it ( during assembly of the cleaned parts the scribed lines on the outside wall will match up and you will know you have torqued them just right). Do one injector at a time and do not mix any components, make a video to know the order of each part and their orientation. I soak all components in some good cleaner for 24 hrs, carb cleaner or brake fluid should work, I have carefully wiped all component with cotton swabs wherever possible. No abrasive pads, files, sandpaper etc to be used, that is obvious why. You could spray some cleaner right into dissassembled nozzles tip and a 5 way stream through the tip should be flowing, otherwise keep soaking them). New hold down bolts and copper washers to be installed for each injector. Also a wise thing to do would be to install the air body into the turbo and connect the map sensors to avoid any codes popping up ( you can install the actual air filters later after car starts)
Since I’ve rebuilt and installed each injector to same position, all is good I’ve been told by dealer mechanic. If you install a NEW injector, the code on it must be programmed into ECU or you will get a fault code and vehicle will likely not start.
So, why the difficulty starting the engine?
It was air in the fuel lines. At the common rail loosen the nuts on outlet line ( 18mm wrench) and then at the side going into injector 17 mm wrench), each of them done one at a time to release trapped air, start with ones closest to fire wall and work your way to the front of vehicle. To release trapped air you crank the engine till air starts bleeding out of line. For me the main battery discharged and I had to put it in a battery charger over night. I mean I was bleeding all the lines for a total of maybe an hour ( should not take as long for some professional lol). It’s a two man job, one cranks engine, the other bleeds the air out).
After full battery charge overnight the suv started the next day by second try, but I knew that ALL the lines going into injectors were clear of air. The suv runs much smoother. I assume some air may still be trapped and the suv will run only better with time. Been told after all that work that even a leak in the fuel lines means that air is entering the lines and could be causing that rough idle, watch for diesel leaks under car after driving the vehicle, that would mean that not a proper fuel pressure is kept and that could be causing the rough idle. Good luck to all

DIY garage

I forgot to mention that the injector holes must be also well cleaned ( big cotton swabs are handy, soaked in good cleaning solvent. Pay attention not to get outside dirt, sand etc into the holes) The cleaned or New injector should be greased with grease available at dealership or same kind as used for sway bars for example), this will ease removal of the injectors in the future.

arto_wa

That sounds good, glad it worked out for you!
Back in 2017 I bought a spare rebuilt OEM injector online from MB dealer for $325

Never needed it so far.

PS.
I think you should use a specialty ceramic grease on these?
(It's available without MB logo for under $10 for 50g jar)

markg612

Nice write up and good work getting it back running again. I’ve been reluctant to tear down the new injectors, did u have any written guidance or did you go at it free hand?

My comments are based on having done the oil cooler (2007 ML) and having had the fuel rails and lines all off, but did not remove the injectors. (Did #4 injector seal after the oil cooler project)

Anyway, after everything was assembled, I let the fuel pump run for a good 5-10 minutes until i heard no gurgling of air anywhere, (had battery charger on battery too). I also had all the return lines between injectors off as well. After that, I cycled the ignition off and back on for start, it took about 10-15 seconds of cranking and it fired off and ran fine.

I’m guessing the disassembly and complete draining of any fuel past the high pressure pump contributed to the difficulties you had? Also, do you think you could be down a glow plug or two? My OM642 was cantankerous with one dead, and even worse with two out (did 3 glow plugs on that engine in 80K miles). In 100K+miles on the 07’ OM648 I’ve not had a glow plug fail, nor on my 2012.

PS, I did NOT torque the fuel lines on reassembly (didn’t have the right crows foot) and paid for that through the nose. I’d done a couple of local runs to ensure it was good to go before a longer drive and thought everything was fine, it was dry. (I use brake cleaner (the good stuff not sold in CA) and compressed air on a warm engine will bone dry clean any fuel away) we were on our way to a friends place about 50 miles from home and boom, MIL light and the engine quit. GRRRR. #2 line at the rail came loose. I got it tightened up to drive, but it was still leaking, the release damaged the seal and threads, and eventually i replaced that line. Idiot, won’t do that again and yes, i have the proper tools now.

arto_wa

Wow, sounds like you were lucky it didn't damage the threads on the injector!

arto_wa

Duplicate post!

DIY garage

So my 2009 ml320 blutec runs smoother during start up but not perfect, during start up and only during first start up of the day I should add I still hear a gurgling sound from under the vehicle, pump likely has some air trapped. Hope it will clear with time.
I have no codes popping up regarding bad glow plugs and to answer the question, I studied YouTube video on someone disassembling either a MB or BMW injector and thought I’ll give it a try to save some $$$ and as described above I was successful I think as time will only tell.
I did run into other problem though. After completing the injector job now I find diesel fuel dripping through the hole at the rubber cap under the torque converter after a short drive. A knowledgeable friend told me it could be the bell housing seal.
Any suggestions or thoughts?

arto_wa

Sounds like a fuel leak dripping to the engine valley either from fuel filter lines, (hp injector lines?) or from the lp fuel return lines?

You said earlier you rebuilt the injectors; did you replace any of the internal parts, or was it mainly cleaning up parts?
Where to get internal injector parts if ever needed - would dealer sell internal injector parts?

Just curious.

DIY garage

Thank you for the suggestion, that is what we are thinking also, that fuel drips down the valley and dripped where described.
As far as rebuilding, it was basically disassemble and cleaning of the injectors. I doubt that dealer would sell internal injector parts, never asked a dealership that question. To be completely honest the injector job did help little but gives me a piece of mind that it’s not them causing rough idle at cold start, once engine warm it’s smooth running. So we figure air is entering the system somehow and causes this issue, once pushed out of the system, smooth running again. The fuel leak did not happen before injector job, so the two issues could be a separate problem. Will keep you informed once problems solved.

DIY garage

To clarify, a mechanic that deals with MB only that I’ve been dealing for years suggested replacing all injectors, knowing of fact that suv has been barely driven over last years. So therefore we undertook the injector cleaning job ( to save $6500 for new injectors and labour). Will head back to him likely for further diagnosis if can’t locate the problem.

arto_wa

Thank you for the reply, makes sense!

The fuel filter rubber lines can leak pretty easy - I put little bit of graphite anti-seize in them in order to make them easier to disconnect and have switched to these hose clamps:




Just a little off the topic note:
I use Opti-Lube summer fuel lube additive at roughly 125% of recommended min dosage all year round in my Diesel car, pickup, tractor & mowers, in order to hopefully extend life of pumps & injectors.

So far so good.

DIY garage

So I’ve managed to locate the fuel leak from under the torque converter at rubber cap. Basically #5 injector( as per firing order), you have to look from top of engine obviously, the one on passenger side closest to firewall was leaking diesel fuel, which then leaked down through some kind of drain hole in the same aluminum block that the injector goes in, (straight to the left of that #5 injector). That hole is located right above the converter and that was the cause of fuel accumulation at rubber cap of converter. Question remains what causes this? The copper washer on injector should be installed with the concave side against the injector tip then into the bore/hole seat, I removed that injector and purchased a new copper washer and bolt (it’s advised these get replaced each time you remove the injector).Also, torque of injector was 7Nm+ as per specs, if earlier before my ownership the injector was installed at higher torque ( beyond my knowledge however) the tread could be stripping slowly and not holding this injector tight as should be. At the end of it all the fuel is still very slowly leaking out once injector in stalled again. Not sure what my next step will be? Possibly spend the $ and get a brand new injector from dealer or even germanparts.ca for some $680 cdn. Will advise if I come up with a solution.
Just to add a note, my buddy replaced the same #5 injector once on a grand Cherokee 3L diesel with same engine, just wondering if this is some flaw in design or a fluke and just coincidence.

GoodByeHonda

Did you inspect the head seat of the injector? Was the surface smooth without any groves? When polishing that surface, you want to continue turning the sandpaper disc (or whatever tool/medium you choose) in one direction only. You do not go back and forth as this will create little channels that will allow fuel to leak from the center out.
The injector close to the firewall on the passenger side is #3 (at least on my OM642).
Regardless, I would carefully inspect the return line connection on top of that injector before you entertain spending any of your money on a new injector.

DIY garage

The head seat has been cleaned carefully 100%, no harsh abrasive has been used, simply cotton swab and a good wiping was done, I’ll inspect the return line and consider changing the tiny rubber o ring on the return as well, thanks for all the valuable advise👍

B34chBum

I just replaced the 2 rearmost injectors, #3 and #6.

First, I may have misspoke about coding-in new injectors.
I understand is recommended procedure due to variance in performance (resonant frequencies) of piezo crystals?
But, my car runs so much better now, no ECU light or related codes - I think from reading more, that injector coding is for emissions control best practice.
It would certainly be bad for serviceability if one had to have or hire someone with XEntry or such, only to replace these. Like in some remote area?
And, it seems the ECU learns and stores fine adjustments to the individual injectors as part of drive cycles in various loads.
I'm going to wait and see, what do you think?

In my case, I put off fixing #6 black death injector for a year or so.
Even with heated up motor, it was stuck hard and I had slide hammer and wrenched on the connection at fuel inlet, before it broke free. Yes, acetone too.
I had done leak down/spill test to find #3 was filling up its syringe in 30 seconds of running, where none of the others even filled to the top of hose.
So I had one bad injector, one Stuck injector with blown seal.
I did bad one (#3) first, to get car running and hot before doing stuck one (#6).

I found pulling the return line off #1 & #2 to have more room to work on #3 - even replacing the orings all three, after warming motor up and doing the #6 injector
, I saw little puddles of fuel collecting on channel on head. I've replaced all 3 on passenger side again, and put a dab of silicone grease on them to get a really smooth locking action.
They seem to get torn very easily, I will need to check again for leakage after a day's driving.

In all other MB applications, the slide hammer would have reached back cylinders okay I think.
But for W251, you also need to pull the wipers, rain tray, and outer firewall partially, to get to rear cylinders.
Then, you can bend the body panel behind the strut tower away from the motor and get the slide hammer lined up. (It bends back easily)

Now to return the cores. BTW, I bought from AutoHausAZ a little over $600 including 50X2 core charge. I think unit price was $259 + tax collected. Shipping included?
These were genuine bosch rebuilt in Turkey.

Thanks to all!

kajtek1

I was pulling injectors on OM642 at 180,000 miles and all of them come with screwdriver push, so you never know.
I heard that injector coding on modern diesels is important, so ECU knows how to doze fuel.
With bad mismanagement the excessive fuel spray can burn hole in piston.

arto_wa

See my previous post #27 above please.

Be aware the M-B manual says clearly:

"When installing new injectors, control units must be adjusted using STAR DIAGNOSIS to store injector compensation coding in CDI control unit"


I wish you well and hope your engine will survive - please keep us posted after few thousand miles under different conditions.

kajtek1

Obviously MB will not tell you that Xentry will code injectors as well.

dhurley

Rapid teach in of injector quantities is done when the vehicle is coasting to a stop for a long distance or when letting the engine be used as a brake to slow down (downshifting and more effective). This method can be used for new injectors that can be coded, or injectors that are replaced and not coded. It will still take a few hundred miles to trim out.

B34chBum

dhurley: Thanks for the reply - I had read 'somewhere' a few peculiarities about the trims, such as the trick of re-entering an injector's current code, and the various trip distances or conditions in the parameters.

My dilemma was finding someone aside from dealer to work on the car in the first place, and not having XEntry myself.
One shop was buried with work, another referred me to a local diesel specialist who doesn't pick up the phone and occasionally replies to emails...
After finding a discussion perhaps here on MBWorld, where owner reported adaptation numbers establishing themselves, I rolled the dice.
So far, motor is much improved immediately, and over the 1st week.

I will update in a few weeks or months.
I should also find and update another thread about cold/hard starting.
I had been playing with the lift pump by key-on, waiting for pump to quiet, and then starting.
(While watching the battery voltage dwindle from repeated unsuccessful cycles.)

Replacing the (1st, over-spilling) injector cured the hard start issue. Replacing the 2nd one (black death) made it even better.
Car now starts within a second of initiating cranking.

DIY garage

So I have put in a used Injector in, replaced one that was leaking somehow, as it was all wet and leaking diesel when installed ( not at return line but right at the seat). All good now and no leakage observed anywhere from it. The suv still runs rough for a few minutes after morning start, slight blue smoke at that time, comes to normal idle after a while. It burns “rich”, meaning that it smells really awful pretty much all the time. I’m thinking that emissions need to be adjusted and I am thinking of coding the new injector. What are your thoughts ? And where do I find the required code on the injector, do I have to pull it out again? How many numbers on the code? I have an expensive Launch programmer that I have been using to clear various codes and I know it has such option to do that. Thanks for any advise on this one.

B34chBum

I re-read DHurley thread:
https://mbworld.org/forums/diesel-fo...-off-stop.html

Which has lots of detail about his experience with coding injectors and how the ECU adjusts injector trim:
"
Update. It appears that the issue has been resolved. It took a while to iron out, but I believe the true issue was simply patience and tool education .

I did have two bad injectors, but I would reset adaptations in DAS -after- recoding the injector. After doing some digging, I found this is not advised. A simple recoding eliminates the need to reset adaptations and doing the latter nulls coding. Resetting adaptations made the CDI4 lose all injector pressure level adaptations.

What seems to have done the trick was to re-enter all injector codes as if they were new, save, and drive. It took longer to recalibrate zero quantity injection over all fuel pressure levels than I anticipated. The levels are 250bar, 600bar, 800bar, 1200bar. The higher levels adapt first.

In my case it took approx 500 miles to adapt the 800 and 1200bar levels with another 3-400 miles to adapt the 250 and 600bar levels.
"


DIY_Garage: If issue is runs too rich or smokes, this sounds like boost leak or boost controller (on side of turbo) malfunction.
But if injector(s) are the cause of excessive smoking, I would think it's because the are worn.
In that case a leak down test (with the clear hoses and syringe vials) would show which ones are having wear issue. You might try this test first.

tjts1

I just took a 17mm wrench and cut it with a Dremel. Worked perfectly. I coded the "new" (ebay used) injector using my icarsoft V2.0.