C250 (1998) TD Not Starting

[GMC]

Hi all

Wifes been on the phone to say the cars not starting, engines turning over but not firing up apparently. I presume there must be some sort of fuel cut out which may be stuck, anyone got any ideas what might be causing the problem

best regards & all the best for Christmas and New Year

GMC

 

[BlackC55]

Air in the fuel system is the most common cause this time of year.

 

[patrick]

had similar issues, if you can, check if there is any voltage been fed to the glow plugs.

 

[GMC]

Air in the fuel system is the most common cause this time of year.

CHEERS FOR THE REPLIES.

Got home tonight and turned it over for several minutes and it eventually got going. Definately air in the system as it took a minute or so of lumpy running to clear. Any idea what the general cause is?? I presume its just shrikage of connections in the cold air. I also can never park with the front pointing up hill as air gets in then as well, in summer or winter

 

[television]

Its often the O rings on the pipes to the pump or filter

 

[hobbsy]

I think I'm also suffering with these.

Just got a mate to pick me up some new lines (about £35 - my local stealer didn't have them in stock).

I'm fitting them tomorrow so I'll let you know how I get on.

Parking on a slope nose up is a bad idea it seems. My drive is on a slope and with all my other cars I back in so I can get a quick getaway in the morning (also useful if rear window is steamed up as can't see where you are reversing etc)

 

[hobbsy]

I'm still haven't got mine to start even after new lines and a new fuel filter and filling the filter with diesel as BlackC55 suggested.

I can see the air in the lines still when its being cranked.

I did about 6x 20second cranks but the battery is starting to go flat so gave up and stuck it on charge.

Should I crank for longer in one go or is there something else I can try.

I chucked another 5 litres of fuel in as it didn't have loads in it, gauge is now showing about 1/3 full.

It is on a slight slope (my drive) with the nose pointing upwards (heard this doesn't help).

Any ideas?

I also fitted new Bosch Duraterm glow plugs yesterday, I didn't check with a meter than they are getting power but I can hear the relay click and the dash lights go brighter when they disengage so assuming they are ok - plus its about 8deg C now so not too cold and I can see the air in the pipes.

Considered disconnecting the fuel pipe that comes from the tank and putting it into a 5 litre can of diesel to see if that helps - is there another filter than could be blocked? The small mesh one in the fuel filter housing is fine.

 

[Parrot of Doom]

Change the o-ring on the fuel pre-filter, part 29 here:

http://www.detali.ru/cat/oem_mb2.as...GM=717.460&CT=M&cat=19S&SID=07&SGR=120&SGN=04

If that o-ring is faulty, it'll draw air in there.

Also check the main fuel filter has the o-ring(s) installed correctly - if it isn't, you'll never get it started. Check that the line (32) (top of the image) isn't leaking.

Normally if everything is ok, there will be a small bubble of air in the pre-filter line (very small) at the pre-filter end when the engine has been rested. If you have a leak there, you'll have a much bigger bubble of air.

New pre-filters do not come supplied with o-rings, they have to be purchased separately.

 

[hobbsy]

I'll check that one, its been out as I've replaced all the lines and I undid that bit and pulled the filter out when I replaced the line.

I think I've cured the root cause of the air getting in my replacing all the lines etc but in doing so there is even more air in there (as the new lines don't come pre-installed with fuel! )

As far as I can see there is no cunning way to get the air out other than cranking and being nose facing up hill apparently doesn't help.

I'll check that O-ring and replace it if at some point but won't be able to get it til Mon or Tues now

What did confuse me a bit is the small o-ring that comes with a new fuel filter. I could see where the big one went on the fuel filter banjo bolt but couldn't figure out where the small one sits. The Haynes diagram didn't really help when compared with reality either.

The big line (marked 32 on that diagram) should be all good as I've replaced it.

I think 2 of the lines look solid with fuel but the rest are either full of air of a bit of mix of fuel and air. Difficult to tell when largely doing this by myself, got the gf out earlier to turn it over while I watch the lines and I could see the air moving along a bit but not very quick etc.

Don't like the idea of cranking it for like a minute solid but from what I've read it seems to be the only way?

I'm going to stick my big jack under the diff and try and get the car at least level or better on my drive to (if that helps!)

 

[LastMinute]

I'm going to stick my big jack under the diff and try and get the car at least level or better on my drive to (if that helps!)

I'm not sure how much difference the inclination makes to a sealed, pressurised system - but if you do do what you've suggested, please be careful. Remember that the parking brake and transmission only act on the rear wheels - so if you lift them off the ground you might find the car coming down the slope to meet you. Can't you just reverse on to your drive?

 

[Parrot of Doom]

Don't crank for a minute solid, you'll overheat the starter motor. Do it for 10 seconds crank, 10 seconds cool down, etc.

You may need a battery charger

The smaller o-ring, I've never found a use for it. You obviously have a bad seal in that area though, as soon as you find it your problem will vanish.

I've not found a diagram that shows how fuel is routed around there, except that line 32 is obviously the supply. This pic could help, its from another forum and show the owner running injector cleaner through his system by disconnecting the fuel tank:

 

[hobbsy]

I'm not sure how much difference the inclination makes to a sealed, pressurised system - but if you do do what you've suggested, please be careful. Remember that the parking brake and transmission only act on the rear wheels - so if you lift them off the ground you might find the car coming down the slope to meet you. Can't you just reverse on to your drive?

Well its just what other people have observed, as you say it shouldn't make that much difference but I'm getting desperate!

Oh and yes I will be chocking the front wheels!

I did reverse on to my drive thats why the front is higher than the back. However I know what you mean - if I could start it up to turn it around I wouldn't have a problem! But that IS the problem - its won't start!

 

[LastMinute]

if I could start it up to turn it around I wouldn't have a problem!

Duh! Sorry...

 

[hobbsy]

Finally sorted, jacked it up and cranked it a bit more, well got the gf to crank it, fuel supply pipe was dry for quite a while. Then saw a bit of fuel, stopped cranking, then on about the 3rd 10 second burst it started.

Thank god for that!

Touch wood should be all good for a while now as I've put new fuel filter, glow plugs and fuel lines in.

One thing I did notice which I didn't notice before (only had the car a few days though) is an intermittent noise which sounds like air being blasted down into the inlet manifold (coming across the pipe that goes left to right of the engine).

It runs and drives find but I wonder what it is.

Are there any cheap diagnostic boxes you can connect to read the codes out on these - OBD2 style?

 

[tlzeebub]

Hi Hobbsy had a very similar problem on my car after changing all the fuel lines and fitting a pair of non return valves/solenoids it still would not start if parked facing uphill, so on Friday i changed the o'ring between the fuel shut off and the pump, left it facing uphill for 2 days and it started ok this morning, job done.

 

[Glenn Smith]

I'll check that one, its been out as I've replaced all the lines and I undid that bit and pulled the filter out when I replaced the line.

I think I've cured the root cause of the air getting in my replacing all the lines etc but in doing so there is even more air in there (as the new lines don't come pre-installed with fuel! )

As far as I can see there is no cunning way to get the air out other than cranking and being nose facing up hill apparently doesn't help.

I'll check that O-ring and replace it if at some point but won't be able to get it til Mon or Tues now

What did confuse me a bit is the small o-ring that comes with a new fuel filter. I could see where the big one went on the fuel filter banjo bolt but couldn't figure out where the small one sits. The Haynes diagram didn't really help when compared with reality either.

The big line (marked 32 on that diagram) should be all good as I've replaced it.

I think 2 of the lines look solid with fuel but the rest are either full of air of a bit of mix of fuel and air. Difficult to tell when largely doing this by myself, got the gf out earlier to turn it over while I watch the lines and I could see the air moving along a bit but not very quick etc.

Don't like the idea of cranking it for like a minute solid but from what I've read it seems to be the only way?

I'm going to stick my big jack under the diff and try and get the car at least level or better on my drive to (if that helps!)

Take the filter off and fill that with fuel, the sooner it fills the better, cranking with no fuel can damage some pumps!

 

[hobbsy]

Take the filter off and fill that with fuel, the sooner it fills the better, cranking with no fuel can damage some pumps!

I did this already on BlackC55's recommendation.

Got it started now anyway.

 

[hobbsy]

As others have said its DEFINITELY worth replacing the o-rings on the fuel shut off valve and the pre-filter.

On the C250TD I found the torx screws quite tight on the cut off valve so although I could just about get on to them with the intake manifold in place it made more sense to remove it so I could really push hard on to them to save stripping the heads.

As dieselman has said (several times!) rev it and see which pipes you see air bubbles in.

Once you've replaced all the problem pipes / o-rings you'll suddenly notice pretty much NO air bubbles in the pipes.