larsianer

I have a w211. 220cdi 2008 with 450,000km.
Are the fuel rail pressure supposed to be 271bar?
When i turn of the engine, and turn the key back to on,(so the fuel pump is running,i guess)

The rail pressure falls to 3 bar in 1-2mins, is that normal, i have new injectors,so they can be leak

Burnzybubbles

The HP pump is mechanical, so when engine isn't turning it doesn't make pressure, 270 bar sounds ok but I'm not familiar with MB engines so it could be off spec, the 3 bar you see with ignition on is pre supply pressure, from pre supply pump I guess, the rate it drops from full pressure could well be normal but it won't be your injectors leaking causing a sudden pressure loss as you'd be getting very smokey starts when you turned the key again.

kajtek1

How does engine starts?
I did not see MB making leak charts available to the owners, but 270 bars drop after 1-2 minutes is definitely too much leak.
Than at 450,000 km you might have more wear parts than the injectors.
What was the reason you replaced injectors? Give us full story?

larsianer

i changed the injectors cause one of them was out of spec,..
the whole story you say..heheh
ok, this is what i remember

i have changed the:

Gearbox
Converter
wheel bearings
all bushings in the suspension front and rear
rear shocks, and air shocks
bushings and arm for sway bar, yes you can purchase them bushings only
drive shaft bearing,with holder
flex plates
engine and gearbox mounts
vacuum pump
map sensor
massairflow sensor
thermostatehousing, with sensor
air tempsensor
top lid on the engine
inletmanifoild,with gasket,and oil seperator
out let manifoild gasket
vacuum sensor to dpf
fuel filter
oil,and oil filter
harmonic ballanser,and all idler wheels
water pump
serpentine belt
alternator overhaul, new bearings, and new ,brushes.
timing chain tensioner
heater valve
change over valve switch
all electric wiering in the engine room, it was alot of work
headlights
side skirts
turbo gaskets
intercooler gasket

And some more parts that i dont remember now.
i had a lot of problem when i got the car,"got it allmost for free"
the only problem i have left, are that its hesitate,allmost like it runs on 3 cylinders on low rpm, i have had a live scan on the o2 sensor,before the dpf filter, and it the curve dont oscilate, so i will get a new o2 sensor on friday, i hope it cures the last problem.
the car was driven allmost 400,000 when i got it, so i have driven it about 50,000

i am trying to learn about the live scan now, cause i think it will help me in the future, i am sure that the hesitate dont are in the gearbox, cause all is new inside,are there any way that i can check the gearbox on live scan?????

you say that 270 bars,leaking in two minutes is to much, where can it leak??

any ideas, of what the hessitate is=?

kajtek1

My son spend 2 years in Technical College to get diesel mechanic diploma.
Still can't get job according to diploma since he has no experience.
I admire your drive to learn the technology, but I only have hope you have enough persistence to succeed.
CDI is still technology old mechanics are learning the hard way, so don't feel bad and when your options ends - take the car to specialist.
You can do leak test on injectors. I know they are new, but S**t happens.
Than you have check valves that could wear out. Not to mention actual external leaks.
First gather technical information. 271 bars is high pressure, but maybe the engine needs more?

larsianer

The specialist in my town,dont know anything, if i say live scan to them,they dont know what it is,they did not know that the seat under the injectors could be cut,worked on to get a perfect seal,there are no diesel near the injectors, i have also tryed with sope water, and no bubbles, my options never ends, i never give up, i have done mechanichal work all my life!

I build snowmobiles and fabricate snowmobile parts allmost every day

Where os the check valves,you write about?
And external leaks, what you mean about that?

I have looked for ages on google, about how much bar the 220cdi fuel rail pressure is

Thanks for reply, hope you understand my english

kajtek1

English is my 3rd language so I have no problem to understand different logic while using English words. What country you are from anyway?
Actually I went on Polish forum seeking answer about the pressure and did not find the number, but few owners of 220 had problem with fuel pressure valve at the end of rail.
One member reported that idle smoothed out once he tap the valve on driver side.
In Poland driver seats on left side - just in case you have right hand car.
Than other member had uneven idle when his alternator sprung clutch froze.
http://www.w210.pl/nierowne-obroty-b...48.html#p59662

PSDCampervan

How are you monitoring your fuel rail pressure? My rail pressure is usually around 340bar @idle & 750bar +or- while cruising at highway speed w/ 1.5 - 2K engine RPMs.

Is this what you mean by Live scan?

larsianer

I have 371bar all the time,even if i give full throttle,i use live scan from easydiag,i have the facelift, do you have prefacelift

What can be wrong, i have no cel,and no error codes??
Kajtek1 i am from Northern Norway,not so far away from the russian border

cmriv

what supplies pressure to high pressure pump?!?!


hmmmm, low pressure pump... aka fuel pump. one thing i see you haven't replaced!

fuel filter and fuel pump are two separate things before kaj tries to start some ishh....

larsianer

So you say that i should check the fuel pump under the rear seat?, can i measure ohm on it

Or just clean it

I will do what you say cmriv, you have given me supreme help before

The strange thing, is that i dont have any check engine lights

cmriv

at your mileage i would visually inspect it. If it looks old/aged dirty ect ect then replace it.

loosing that much pressure in a short time would lead me to believe it's the low pressure pump causing the issue.... You have a fuel pump relay as well. It could intermittently be sticking.... a volt meter will tell you all u need to know.


weak pump wont throw cel...

larsianer

The fuel pump reley,is it in the fuse box in the engine room?
I will open the rear seat tomorrow and check it

cmriv

Should be in rear sam but i'm uncertain with a diesel...

larsianer

I did take out the fuel pump today, i was warm, and the lid over the fuelmpump was also warm, that cant be right

What you think?, there was some few air bubbles when i drove the fuel pump

kajtek1

I think what you meant to say was "it was warm"?
Pump is compressor and high-pressure one.
Lot of energy to compress has a by-product as heat, so warm pump is normal.
Now air in the fuel is not. Recheck all your hoses.

larsianer

Yea i meant it was warm,,,my ipad sucks
Shall it be no airbubbles when i start the pump??

I think i will try with a new pump also, the car graveyard near me can sell me a cheap used on, for about 40-50usd