w123 230CE suddenly won't start

RossCormack

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Hi! I hope someone might be able to give some initial thoughts to my problem. My 230CE wouldn't fire the other day. I thought I had just run out the fuel so I put some in but then discovered the problem persists. I haven't been using it much but it has been sitting outside. I have only been starting it up and letting it turn over a bit (why I thought I was out of fuel). I hope to have a look on Friday and see if fuel is getting to the engine or not and will check there is a spark. I suspect faulty fuel pump. Does anyone have any other ideas? Has anyone experienced this problem? I will update this when I know more, but would really appreciate anyone's input, thanks.
 

grober

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Chances are you have a bit of condensation inside the distributor cap. TAKE IT OFF [ taking a note of where all those plug leads go! remove the rotor arm and give its contacts and all the all the cap contacts a clean up with a small file till they are bright metal. Then give it a good wash with WD40 or similar and dry it off thoroughly. Check the cap for signs of cracking or ht tracking and replace it if suspect. Finally give it a dry off with a hairdrier along with the open body of the distributor. You can try starting again at this point or you could take out the spark plugs and give them a clean/renew them and check the gaps.
 

Pontoneer

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I agree with the above - also check under the bonnet for any vacuum pipes that may have come adrift or vacuum hoses that may have split : no vacuum = no induction .

You should hear the fuel pump run for a second or so if you just turn the ignition on without trying to start the engine - if need be , keep the drivers door open while you listen for this under the back of the car . If you don't hear the pump running , I expect a W123 will have a fuel pump relay like later cars - this just could be the culprit , although they usually go intermittent due to dry solder joints making and breaking rather than working one day and stopping altogether the next . Otherwise crawl under the back and put a meter onto the fuel pump to see if power is reaching it .

If none of this helps , please come back to us .
 

BlackC55

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Check if the breather pipe under the inlet manifold is still connected
 

Pontoneer

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Check if the breather pipe under the inlet manifold is still connected
That one happened to my 300TE !

Returned to car after being parked for 20 mins - nothing !

Went through everything I could think of - couldn't see anything wrong - ended up using my girlfriends AA cover as she was with me - AA man was baffled too , nothing on his laptop to help - as a last resort he phoned a friend ' who knows about Mercs' and was told to check for this .

The pipe was almost impossible to see , even with the air cleaner off , but had split at the end . Some insulating tape and a 'tie-wrap' around it got me home , then I ordered a new one .
 

jaymanek

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fuel pump relay is a common problem which is located inside the car, passenger side, above where the bonnet release is.

Easy to diagnose, turn key, can you hear buzzing from the back of the car.
 

Pontoneer

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fuel pump relay is a common problem which is located inside the car, passenger side, above where the bonnet release is.

Easy to diagnose, turn key, can you hear buzzing from the back of the car.
It is useful to know where it is !

I never had a problem with any of my W123's , possibly because they were all relatively new when I had them .
 
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RossCormack

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Sep 21, 2009
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Yes, the buzz from the fuel pump was still there. I took the distributer cap off and cleaned it a bit then applied some WD40. After that, the car started and I went for a drive. I didn't try to start the car before this because the battery was so low and I wanted the best chance but it looks like it was condensation, which dried becaue of the hot weather or was fixed by the cleaning. Thanks everyone.
 

vijilants

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Also really important that the ignition components are oem....Bosch.

Non oem parts on these vehicles really do throw up some odd faults that can sometimes really give you headscratching moments.
 

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