engine being starved of fuel - w203 cdi 220

[Dirtyharry]

model 220 CDI - 2002

problem - engine being starved of fuel.

last week my car wouldn't start, the engine would turn over but it wouldn't bite. I called the RAC and I was told the engine was
being starved of fuel (diesel). the fuel gauge was showing 1/4 of a tank but we still added 5 litres just incase the fuel gauge was wrong.
after adding the extra 5 litres the car started first time.

with further investigation by a professional, it appeared that the uplift pump from the fuel tank wasn't functioning properly. A new uplift pump was
installed and the car work perfectly for one week.

but today the car was parked on a down hill slope and didn't start, same problem as before. I managed to get the car on a level surface and it started first time, weird.

does anyone have any ideas what the problem could be ??

Thank you

 

[Dirtyharry]

update:

I now have the following symptoms when the car is warm, cold starts are fine and the fuel problem is ok.

when the engine reaches 80c the car will not re start after a short stop. if the temp rises to 85c or drops to 60c the car will start. also the turbo will cut out once the temp reaches 80c.

new fuel pump & crank sensor haven't made any difference. I'm going to have a diagnostics and injectors check, if this doesn't solve the problem , then I'm stuck.

I would just like to add, the crank sensor was a Bastard to change, most awkward place behind the engine. 6hrs hours later Grrrrrr

has anyone had problems starting their W203 when warm ??

ta

 

[BlackC55]

Get the live data for the injectors looked at on a star. The faulty injector should show itself. Also get a leak off test done too. This will also show up faulty injectors. A diesel specialist can do it.

From what you have just said I would say an injector problem is your most probable cause.

 

[Dirtyharry]

that is my next step. i just hope one of the injectors is faulty, i'm 400 down already.

thanks for the advise, appreciated.

 

[BlackC55]

Anytime...........

 

[Bolide]

For other diesel mercedes, trouble starting on an uphill slope is caused by air leaks in the fuel system. I suspect the same is true for your car

If you have problems that are difficult to track down & confusing symptoms I suspect you have more than one fault

Nick Froome
www.w124.co.uk

 

[television]

As bolide, air leak fits the bill after having a new pump, also starting facing up hill, the air leak could also be in the return to tank pipe work

 

[Dirtyharry]

after my original post regarding the fuel problem, I have realised that the issue isn't related to hill starts etc. sorry :roll:

I'm hoping its the injectors as the car will start first time when its cold but when it reaches 80c, it won't start and the turbo will stop working.

post to be updated when the injectors have been checked

thanks

 

[BlackC55]

I do not know of any CDI models sufferering with air leaks. Correct me if I am wrong. The more knowlege the better!!!

 

[dava]

The only problem I know of is the black plastic valve on top of the fuel filter. for some reason, usually after a filter change, this either allows air to pass, probably the seal and also some times allows fuel to drain back. Happily they are cheap to replace.

 

[hmang]

The only problem I know of is the black plastic valve on top of the fuel filter. for some reason, usually after a filter change, this either allows air to pass, probably the seal and also some times allows fuel to drain back. Happily they are cheap to replace.

dava
are you talking about the valve / union that is integral to the filter housing cap ?

 

[dava]

The black plastic on top of the filter held in by two torx screws with two hoses connected. We buy them for .60p so worth a try.

 

[hmang]

i know the bit..

2 x torx, twist and pull...got that on my v class but it's counterpart on all my cdi is part of the filter housing lid

none of mine are 203,s though

 

[Dirtyharry]

update.

had all four injectors replaced at a cost of £730 but i still have the same problem.

engine reaches 70-80c and the turbo cuts out, if i stop for fuel it won't re-start until the temp drops to 50c. cold starts are fine.

i'm resigned to the fact that MB need to see the car to get it fixed. i'm sure its something electrical.....

new parts fitted, crank sensor, fuel pump , 4x injectors £1000 . boy am i ****ed. i would never buy another Merc .

 

[mattkh]

i'm resigned to the fact that MB need to see the car to get it fixed. i'm sure its something electrical......

Hi
Faulty fuel thermostat

 

[wgriffiths]

none start when warm

update:

I now have the following symptoms when the car is warm, cold starts are fine and the fuel problem is ok.

when the engine reaches 80c the car will not re start after a short stop. if the temp rises to 85c or drops to 60c the car will start. also the turbo will cut out once the temp reaches 80c.

new fuel pump & crank sensor haven't made any difference. I'm going to have a diagnostics and injectors check, if this doesn't solve the problem , then I'm stuck.

I would just like to add, the crank sensor was a Bastard to change, most awkward place behind the engine. 6hrs hours later Grrrrrr

has anyone had problems starting their W203 when warm ??

ta

hi m8 just reading your simptoms youve not said if it cranks or turns over common fault on c220cdi especialy is the starter motor

 

[Ellsy Tanners]

Hi there
This is a very interesting one. As you have had no star test i assume you havent obtianed any fault codes, if any are there.
A problem i have had before that sounds similar to this, was down to an implasuable reading from the oil temp/ level sensor which played up during a specific tempurature range. this put the engine into emergency mode, (no turbo), to protect itself from causing damage. This is just one case but could be along the lines of your fault.
Next time it wont start try to do a oil level check in your cluster, if it wont work at all this could be your fault.

To diagnosis it correctly a star test will be needed to be honest sorry to say

 

[wgriffiths]

hi just reading your problem with the starting on your cdi ive seen this problem on a couple of w203 modles before check high presure pump return presure or presure at the y94 fuel rail presure releaf valve if this is ok could be the sender units in the tank as the hole system depends on return presure when the fuel is returned back to the tank it goes in the nsr sender the sender has a pick up on the retun when the fuel goes in though the pipe it bends sharp 90 degrees at the bottom of the tank where there is a pick up this has a sifening effect then transferes the diesel from ns to os of the tank when the fuel is in the os of the tank the low presure pump sucks it back to the front this is why the car started when you put diesel in the tank as it goes straight in the os of the tank

 

[Ellsy Tanners]

There are so many posible cause for this, a star check will tell if there is fuel pressure and its electrical or no fuel pressure and the faults air getting into the system somewhere as the other guys say.

when it wont start can you see fuel in the clear pipe running from the filter to the low pressure pump?

 

[wgriffiths]

fuel in pipe

hi there can be fuel in low low presure pipe but if rail presure is below 258 bar it wont start there is only a few things that can stop a cdi starting as a short test on star showing a fault yes will be helpfull but if it is the sender unit no reading or test can be carried out its down to experiece and product knowledge with 15 years working on mercs and diagnostic mb tech qualifications behind me without seeing the car it will be one of these items if he replaced the injectors and the other items