Fuel fuel starvation 200m after fuel filter change

[nujon]

W203 C220 CDI - changed fuel filter @ 70K miles - started on 2nd attempt - ran fine for ~ 200miles then stopped dead and will not restart!; viewing clear fuel pipe from filter to lift pump shows only a sporadic dribble on cranking (everything fine before filter change)

Anyone any advice please?

 

[Ian B Walker]

Have you put the pipes on the filter in the correct order?

 

[nujon]

Yes - can only go on one way - filter to lift pump is 'plug-in' type connector to central socket on filter wheras inlet to filter (from fuel pre-heater) is clamp type to elbow on filter

 

[Dai rees]

Have the "O" rings failed, -- it does sound as though the system is drawing in air from somewhere

 

[Baron_Samedi]

Is it possible that the fuel pump has failed?

A friends SLK did this recently...

 

[nujon]

The pipes to/from the fuel filter were inevitably disturbed to fit the new filter - the outlet pipe to the lift pump having 'plug-in', o-ring sealed connectors at either end - hovever the o-rings showed no evident damage. The inlet hose to the fuel filter was originally fitted with an MB clamp ring - this was damaged on removal so I replaced it with a jubillee clip - maybe not a good idea?

Does anyone have any experience of (i) apparently good o-ring seals on the lift pump suction side actually allowing sufficient air ingress to frustrate the lift pump (ii) use of jubillee clips on the filter inlet allowing significant air ingress?

 

[cyberflex]

As silly as this may sound, what make fuel filter was it? I had all sorts of problems with starting/cranking recently directly after a fuel filter change,later I changed fuel filter to a Bosch item from ECP and all the problems went away immediately. W203 C320.
I shall not name the make of the fuel filter, but they are a well known brand and used alot by OEMs, 2 filters of the same make and the same symptoms of failure within days,faulty batch???? I then changed to a Bosch and all has been fine for months. I shall only use Bosch in future.

 

[nujon]

Make was something like marf backwards - your theory had crossed my mind too!

 

[cyberflex]

Nah, it wasn't them, they are OK, plenty of places use them, I have never used them though, to be honest in the past I have used Hengst aswell and always been well happy, ECP seem to do less Hengst now, but just to add to my previous post I would use Hengst aswell as Bosch without any hesitation, both these are top quality IMHO. Try and get hold of a Bosch or Hengst, you can't go wrong with either IMHO. It was the first time I used this 'other' make and the last, I do not care how big a reputation they have within the trade, I had 2 weeks of hell from my mum,"the car takes ages to start" ,"the car stalls" and alot more besides... all over what turned out to be 2 faulty fuel filters from the same brand, apparantly collapsing internally within days of their installation.
Anyway, just try to get a Bosch or Hengst and you may solve the issue immediately.

 

[nujon]

Thanks cyberflex - have bought new Bosch filter and inlet/outlet hoses + clips ex MB - will fit tomorrow and hope for the best!

Re. the lift pump - does anyone know if its positive-displacement type and hence self-priming or centrifugal and requiring a flooded suction to prime?

Also, I presume it would do no harm to pre-flood the new filter (I did not do this with the one fitted last week)

 

[nujon]

Well fitted new Bosch filter and new inlet / outlet pipes - all pre-flooded - but no joy - engine turns over vigourously but will not even try to start - anyone any ideas before I call the garage. (when the engine originally cut out - that was totally without warning - no spluttering/misfire - just off like turning off the ignition!)

 

[cyberflex]

Hi, sorry it has not resolved your problem, in the petrol version I guess the next step would be to check fuel pressure in vicinity of injectors, change CPS e.t.c.
I think, maybe wait for someone to chime in that is familiar with the CDI setup. Could be a faulty fuel relay, without a proper Star diagnosis, we are just speculating I guess, is there anyone local to you with STAR??

 

[BlackC55]

Well fitted new Bosch filter and new inlet / outlet pipes - all pre-flooded - but no joy - engine turns over vigourously but will not even try to start - anyone any ideas before I call the garage. (when the engine originally cut out - that was totally without warning - no spluttering/misfire - just off like turning off the ignition!)

It is a possibilty that one of the injectors are leaking off too much. Do a leak off check first.

 

[nujon]

Thanks for the comments - how do you do a 'leak off check' please?

 

[BlackC55]

You need a leak off test kit.

Any decent garage should have one.

 

[nujon]

Thanks everyone who has heped me on this one

Mate who runs a local garage has come up and STAR checked the car - no error codes showing (with ignition switched on). He admits he has never done much work on the W203 CDI per-se but plenty on CR engines in other makes. His hunch before getting the tools out is that the problem is electrical and quite possibly a failed CPS - he's going to take the car in next week