c250 TD starting problem

[tomted]

Hi all,
i have a 98 C250 TD, lately finding it very hard to start, the engine is turning over but will not fire. i have replaced the heater plugs and battery but still no difference.

 

[poisas]

there is no diesel, or/and no pressure ;D

 

[Dieselman]

Suspect an air leak into the clear fuel pipes. Replace the pipes or O rings.

 

[swampea]

Hi, I seem to be having the same problem. Same car, but a 97' high milage.

Recently changed the plugs, the battery is fine.

Initially, after changing the plugs everything was fine, but a week or so on and the car has trouble starting from cold. usually about 3 or 4 times cranking at about 20 secs a go. once it gets going its usually fine for the rest of the day.

I''ve checked fuses and relays, seems the glow plugs stay on for about 20 seconds and all are definately working with correct voltage.

I'm suspecting a fuel issue.



Tomted- sorry if i'm hijacking this thread, but it seems we are having the same problem. please let me know if you solve yours.

Thanks.

 

[swampea]

I've just had a tinker with the car and found a fuel leak (pictured) could this be the cause? i'm assuming that if it leaks with the engine running then it will take on air with the engine off.

Also, although the noticable big leak is only on the closest pipe in the picture, the other pipes seem to have minor leaks as well (the furthest away in the pic)

Could someone tell me what i need to replace here to stop the leak, and hopefully stop the starting problems.

Thanks

 

[SilverSaloon]

hi

your delivery valve seals are leaking. Common problem. Replace the rubber delivery valve seals with care!

you need to replace the rubber o-rings and the copper washer.

all the info you need is here:

http://www.mbclub.co.uk/forums/showpost.php?p=618127&postcount=124

i preseume the o-ring sizes will be the same on your 605 engine - but you will have slightly different clear pipe shapes....

there is a how to on here that covers it:

http://www.mbclub.co.uk/forums/showthread.php?t=46736

also see this and the link within:

http://www.mbclub.co.uk/forums/showpost.php?p=618128&postcount=11

you should replace all these at the same time and your car will then start 1st time. Do the pre-filter, main fuel filter and the tank strainer at the same time.

if in doubt, get a specialst to do the job for you - there are some horror stories on people really screwing up their engine by doing it wrong/badly etc. Although i feel with care any DIY mechanic can have a go (i did with success)

have you been running on veg oil?

Read the whole thread here, that covers all the issues i had with my fuel leaks etc

http://www.mbclub.co.uk/forums/showthread.php?t=49844

Horror story links are here:

http://www.mbclub.co.uk/forums/showthread.php?t=55297


fuel tank strainer (yours may be very different though) info here:

http://www.mbclub.co.uk/forums/showthread.php?t=55663&highlight=tank+strainer

 

[swampea]

Hi Silversaloon,

Thank you very much for the info, very comprehensive 'how to'.

I'll get on to this job as soon as i get all the parts.

I havent used veg oil on it yet (am considering it when it gets a bit warmer), but have only had the car for a month so don't know what it was running on before.

I did run some injector cleaner through the system recently so perhaps that finished off the O rings.

Thanks again for the help, i'll let you know how it goes.

 

[cowley]

bad starting C 250 TD

I had similar bad starting problems, changed all fuel pipes O-rings, pre-filter and filter. still had problems. It turned out to be the crankshaft sensor.