ML 270 CDI 2003 - engine shuts down on kickdown

[vbox]

I have a serious problem. When you give the car a big peddle to the mettle kickdown at 3000 revs EPC light comes on and engine loses all power until finally dies. (No power steering is scary!!)
Car runs perfectly on normal driving and normal kickdown, only when full throttle is applied aggressively does it happen.
ESP/BAS light has been on for a couple of weeks but do not think this has anything to do with it.
Have no external leeks. Have just fitted new seals to all injectors and replaced orings and seals to High pressure injection pump thinking this would cure it.
Have had diagnostic and "common rail monitering" came up. Does not pinpoint anything. Difficult to diagnose source.
Anybody out there had this problem or have any ideas???

 

[AndyPCD]

Hi and welcome

Have you tried fitting a new fuel filter to the car i have seen this hapen when they have a slight blockage in them

 

[big john]

my 320 cdi did this it was a low voltage battery check the batt if voltage not hight enough will bring the lights on wourth a check

 

[vbox]

thanks for the promp reply guys.
Not changed fuel filter. Easy fix if this is the case. Would engine not be missing at other times? Runs perfectly until you give it a bootfull of throttle...
Battery low voltage is a strange one....Again would this just switch engine off only when large kickdown applied.
Let me know your experiences in a little more detail. I am intrigued and hopeful it is a simple fix. (convinced this was an expensive investigation)
Waiting for you in hope...

 

[AndyPCD]

the reason it runs fine under normal driving as the fuel filter might only be partially blocked so the fuel can flow normally under driving but when you give it a boot full the fuel cant flow quick enough to feed the engine so the engine cuts out and gives you the fault codes your getting

 

[dokalj]

Whats the typical costing of a fuel filter/ fitting and how do you know when yours is on its way out?

vbox look through your service history has it been changed in the past 4 years? As MB recommend every 4 years.

 

[EDZ649]

Not MB but my Mitsubishi L200 fuel filter has to be changed every 25K

 

[AndyPCD]

They vary from about £15-£55 depending on what type of filter is fitted.

You cant really tell when it is on its way out but as per mercedes instructions they reckon they last about 4 years

 

[dokalj]

Yeah, why does the ML's fuel filter have to be changed every 4 years as other manufactures have longer periods?

 

[AndyPCD]

Its not just the ml that is changed a 4 years it is all the merc range. Who knows why mercedes have said four years because as edz649 said his l200 is replaced at 25k miles

 

[vbox]

the reason it runs fine under normal driving as the fuel filter might only be partially blocked so the fuel can flow normally under driving but when you give it a boot full the fuel cant flow quick enough to feed the engine so the engine cuts out and gives you the fault codes your getting

Thanks. Sounds plausable. One more thing to mention, when stationary in Neutral giving it a bootfull does not cut engine. Seems to be only when driving. Is there an explanation for this??

 

[AndyPCD]

Even though you give it a boot full when it is at idle it still doesnt use as much fuel as when it is under load and driving as you have the turbo etc work flat out so needs as much fuel as possible going in.

Do you have a good independant in your area that could have a look at it

 

[vbox]

I do hope you are right.
Have spoken to MB IND. specialists and a diesel specialist who say it is a difficult one to diagnose. Have been advised a leak test on injectors alongside other things. Could be an expensive search!! Hence my delight when you came up with fuel filter change.

 

[AndyPCD]

Not being funny but a mb and diesel specialist should have an idea what is up with your car.

Do they have a star machine to test your car as this is worth its weight in gold with the info you can read what the car is doing if it being used correctly

 

[EDZ649]

It could also be the diesel pump itself that is on it's way out. They often start to break up inside.

 

[vbox]

Not being funny but a mb and diesel specialist should have an idea what is up with your car.

Do they have a star machine to test your car as this is worth its weight in gold with the info you can read what the car is doing if it being used correctly

Diesel specialist showed Common rail monitering on his machine. MB specialist does not have a live diag machine so think it would show same fault. Guess they are saying unless you are in the car when this happens with the correct equipment they cannot be sure of cause.
Do you think their machines should be sussing this out??

 

[AndyPCD]

It is a lot harder when you dont have live data to look at but if they are any good at their jobs they should be able to diagnose the fault.

 

[vbox]

It could also be the diesel pump itself that is on it's way out. They often start to break up inside.

Interesting one. How do you explain car running perfectly at all other times and only has problem when hard kickdown applied?!?
Also, any idea on cost of new or recon pump if this is the case??
Thanks in advance

 

[vbox]

It is a lot harder when you dont have live data to look at but if they are any good at their jobs they should be able to diagnose the fault.

Fair point. Will try and fnd someone with live data capability to save time and money.
I will first change fuel filter and hope you were spot on with your diagnosis.
Thanks v.much for your thoughts on this.

 

[AndyPCD]

Its the cheapest option to go for first before you start looking at pump and injectors etc