W203 220cdi Starting issue

[dvdmike]

Hi all,

Having an issue and in need of help please!!!

I had an issue with my 2002 c220, and it was leaking fluid, it failed the MOT and it turned out the fuel pump was leaking badly and they installed a recon unit.
Now a week later it will never start first time, it turns over but it takes 10 mins to fire (not 10 mins of cranking but trying and then waiting and trying again)
The first time you try it fires up but then cuts out (even if you rev the engine)
When you turn to position 3 you can hear pumps running, but it just cranks and wont fire.
I am a half layman so have no idea what it is.
If it sits for say 3-5 hours it will fire first time, but more than that is less likely.
Could it be the fuel filter? it needs a service, but I know that wont have anything to do with the ignition or fuel system.
I have used Red X on it to see if it was a fuel issue and its still there.
The ignition did blow a fuse a few months back and that was replaced.

Thanks for any help

 

[whitenemesis]

Air getting in the fuel line, check the condition of any 'O' rings

 

[m80]

Early 203 has 'o' ring seals at the ends of the fuel pipes. They harden / flatten and allow air ingress. More so when colder outside.

They cost peanuts but you can cause damaged to old brittle plastic removing the ends to replace the 'o' rings.

Source the rings from a genuine Merc dealer, local or MB Newcastle from eBay.

Pre warm the engine bay and prise the clear fuel line end clips off carefully. There are 6 or 7.
Often it is the centre 'o' ring at the fuel filter that is the culprit. I've cheated in the past and removed, wrapped in PTFE and reinserted.
Not a silly way to diagnose.

 

[dvdmike]

Is this easy to do myself? Do I need a ramp or a pit to do it?

 

[m80]

All easy, just work within engine bay with bonnet up. No more than that.
Follow your clear fuel lines to their ends.
You 'might' feasibly get a clue if you can see where the air bubbles are while cranking.
But tbh replacing all 'o' rings is cheap and easy.

 

[dvdmike]

Thanks the O rings that need to be changed are engine side? Would this have been made worse with the fuel pump change?

 

[m80]

Nope,
I would be surprised if they haven't been changed a couple of times already.

 

[dvdmike]

It is a messy job? will I lose a lot of fuel?

 

[m80]

Nope,
keep some kitchen towel, or similar, handy to catch the drips.

 

[dvdmike]

I am rubbish at all this, but will give it a go, thanks

 

[m80]

What's the worst that can happen?




BOOM!

 

[dvdmike]

What's the worst that can happen?




BOOM!

I have set myself on fire before.....

So just pop the lines off and then replace the O rings, then pop back on?

 

[dvdmike]

Having a look at images on the net and under the bonnet I can't say definitively where the lines are I need to sort.
Is there an idiots guide?

 

[Petrol Pete]

The 'Idiots guide' Might read something like this .

"Dear idiot , take your car to a qualified mechanic..."

But as the job has been described as an easy DIY if I were you I would have a go at it

 

[dvdmike]

Bit rude

 

[BlackC55]

All the clear fuel pipes on to of the engine have seals on both ends. I expect they have been done in the past on a car of that age. I would replace the pipes too as they often are brittle. A set of pipes are available from your local MB dealer. Just ask for the clear fuel pipes.

 

[dvdmike]

All the clear fuel pipes on to of the engine have seals on both ends. I expect they have been done in the past on a car of that age. I would replace the pipes too as they often are brittle. A set of pipes are available from your local MB dealer. Just ask for the clear fuel pipes.

Thank you