1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

c250 td fuel problem---lift pump ?

Discussion in 'Engine, Drivetrain, Fuel and Exhaust' started by rustynuts, Dec 24, 2012.

  1. rustynuts

    rustynuts Member

    Messages:
    10
    Likes Received:
    0
    Joined:
    Dec 24, 2012
    Your Mercedes:
    C250TD
    Hi everyone ,i,m new to the forum, and have a problem with my 99 c250td, i stupidly decided to add some veg oil to the diesel,and all was going well
    ,then it became problematic to start,
    ive changed the pre filter and main filter,and blown the feed and return lines to the tank,and added about 15 litres of new diesel. ive used a bulb primer and sucked about 4 litres of fuel through by temporarily attaching the primer bulb to the fuel line from the lift pump to the pre filter.
    if i fill the main filter, and crack the injectors at the head, the car will start and run fine and rev up until the filter empties,
    Im thinking my lift pump may be at fault,as im getting no fuel pumped to the pre filter,if i crank the car over,
    what do you guys think,

    many thanks in advance for any help
     
  2. Steve@Avantgarde

    Steve@Avantgarde Forum Supporter Authorised Forum Supporter

    Messages:
    6,825
    Likes Received:
    1,003
    Joined:
    Dec 8, 2009
    Location:
    Bristol/Somerset
    Your Mercedes:
    C220CDI AMG Line Premium, SLR McLaren Roadster, SL55 & C32AMG
    I would add 5 Litres of unleaded to the tank, that will act as a detergent and help pull it through. Take all the plastic fuel lines off the diesel pump and clear them through.

    Its weird you should have this issue as I run my C250TD on WVO converted into bio-diesel and have had no issues at all and these engines are known for running SVO with no issues too although I never do it myself.
     
  3. Some guy on the internet

    Some guy on the internet Senior Member

    Messages:
    1,350
    Likes Received:
    9
    Joined:
    Jan 21, 2010
    Your Mercedes:
    A few.
  4. CRH71

    CRH71 Senior Member

    Messages:
    90
    Likes Received:
    0
    Joined:
    Jun 11, 2012
    Location:
    Kent
    Your Mercedes:
    C250 TD
    You haven't got knackered fuel pipe seals, have you? I'd doubt it's the lift pump as I hear of those going on as long as the engine with no issues. However, it's not unknown that a higher-viscosity fuel could cause the lift pump to draw air past any of the fuel system o-rings due to the massive volume of fuel that these pumps turn over.

    Mine's just started drawing air in when exceptionally cold, and it's the same age/mileage/model as yours, but it's been run on pump diesel from day one of it's life. If my o-rings are knackered, and they've been run on pump fuel, at the mileage/age that it is then it's a fair bet that yours are probably in a worse state after having to have dealt with thicker and more viscous SVO.
     
  5. brianbrian

    brianbrian Senior Member

    Messages:
    2,747
    Likes Received:
    181
    Joined:
    Sep 27, 2008
    Location:
    cockney in the West Country
    Your Mercedes:
    w124 250D, SL129-deisel
    Have you cleaned (changed) filter in the tank. Hope this helps
     
  6. FIBAMAN

    FIBAMAN Senior Member

    Messages:
    343
    Likes Received:
    0
    Joined:
    Nov 13, 2006
    Location:
    TYNESIDE
    Your Mercedes:
    C180,C180,E300TURBO DIESEL
    It could depend on how much veg oil you put in initially.
    I ran my E300 TD on mix of 50% in warmer weather (above 10*c) and only 10% at temperatures below 10*c.
    Veg oil can "wax" up at colder temps.
     
  7. OP
    rustynuts

    rustynuts Member

    Messages:
    10
    Likes Received:
    0
    Joined:
    Dec 24, 2012
    Your Mercedes:
    C250TD
    hi thanks, is there a tank filter on a 99 250td, i cant find one on mine,ive read many posts saying there isnt on on a 250td
    thanks
     
  8. OP
    rustynuts

    rustynuts Member

    Messages:
    10
    Likes Received:
    0
    Joined:
    Dec 24, 2012
    Your Mercedes:
    C250TD
    hi thanks, mine was run on a max 50/50 mix
     
  9. spock500

    spock500 Senior Member

    Messages:
    890
    Likes Received:
    2
    Joined:
    Apr 5, 2008
    Location:
    Milton Keynes
    Your Mercedes:
    300TD, 1998
    What is your fuel gauge reading?

    Anything under a half tank will cause problems with veg oil due to saddle tank set-up (see above link).

    Brim the tank with diesel which should get you going. Engine wise, steer clear of soya as very sticky. I have just filled mine with Sunflower ahead of travelling tomorrow.
     
  10. OP
    rustynuts

    rustynuts Member

    Messages:
    10
    Likes Received:
    0
    Joined:
    Dec 24, 2012
    Your Mercedes:
    C250TD
    hi thanks, mine was run on a max 50/50 mix
     
  11. chizzel89

    chizzel89 Senior Member

    Messages:
    345
    Likes Received:
    0
    Joined:
    Feb 27, 2011
    Location:
    Pembrokeshire
    Your Mercedes:
    Mercedes-Benz C250 Turbodiesel Sport Auto. Estate. 1998. 180,000 mls
    Sounds like either the tank isn't full enough or the O-rings on the pipes, pre filter and shut off valve are knackered (very likely).

    My C250TD is basically standard but has had ALL the O-rings replaced and I have started it at sub zero temperatures on 95% WVO 5% petrol with no real issues. Granted, it clattered badly for the first mile but after that it was fine.

    If the lift pump had failed (not much to go wrong with them, but a non return valve could get jammed) it wouldn't run at all. Sounds like an air leak.

    There is no tank strainer. The only strainer on the car is a small gauze which is located where the fuel feeds into the main filter housing. You undo a 6mm hex bolt, pull the push-fit pipe off (get new O-rings first), then prise out the pre-filter.
     
  12. OP
    rustynuts

    rustynuts Member

    Messages:
    10
    Likes Received:
    0
    Joined:
    Dec 24, 2012
    Your Mercedes:
    C250TD
    thanks for that, should the lift pump,pump fuel to the pre filter if i crank it on the starter,
     
  13. television

    television Always remembered RIP

    Messages:
    164,074
    Likes Received:
    309
    Joined:
    Mar 14, 2005
    Location:
    Daventry
    Your Mercedes:
    2002 SL500, 216 CL500, all fully loaded
    That is interesting and 53 is not fitted to your car so it does nor have one

    [​IMG]
     
  14. Some guy on the internet

    Some guy on the internet Senior Member

    Messages:
    1,350
    Likes Received:
    9
    Joined:
    Jan 21, 2010
    Your Mercedes:
    A few.
  15. television

    television Always remembered RIP

    Messages:
    164,074
    Likes Received:
    309
    Joined:
    Mar 14, 2005
    Location:
    Daventry
    Your Mercedes:
    2002 SL500, 216 CL500, all fully loaded
    Some times there are variants and not the first time someone has said someone has not got something when they have :D:D
     
  16. OP
    rustynuts

    rustynuts Member

    Messages:
    10
    Likes Received:
    0
    Joined:
    Dec 24, 2012
    Your Mercedes:
    C250TD
    Ive got it running by brimming the tank and fitting a primer bulb in the fuel line before the lift pump,primed it and it started and run fine for 10 mins then spluttered and cut out, after a lot of cranking it started,ran for a while then spluttered and died again,air bubbles in pipes,must be the seals,
    is there a kit you can get with all the seals in and a diagram of where they are located
     
  17. television

    television Always remembered RIP

    Messages:
    164,074
    Likes Received:
    309
    Joined:
    Mar 14, 2005
    Location:
    Daventry
    Your Mercedes:
    2002 SL500, 216 CL500, all fully loaded
    There is, do you mean like this, but "some guy on the internet" will come back and complain

    [​IMG]

    № Код Название,
    Информация Кол-во Прим.
    005 A 6010920408 FUEL FILTER 001
    008 A 6010900352

    Замена:
    A 6010901452
    A
    FILTER -
    008 A 6010901452

    Замена:
    6010901552
    FILTER,
    (parts kit),fuel filter 001
    008 A 6010901552

    Замена:
    6010901452
    FILTER,
    (parts kit),fuel filter 001
    011 A 0099978148 SEAL RING 001
    014 A 0099979248 SEAL RING 001
    020 A 6049900063 HOLLOW SCREW 001
    026 A 6010920105 FILTER ELEMENT,
    Prefilter 001
    029 A 6019970148 SEAL RING,
    Prefilter 001
    032 A 6050700032

    Замена:
    A 6050701432
    A
    LINE -
    032 A 6050701432 LINE,
    From thermostat to prefilter 001
    035 A 6019970445 SEAL RING 001
    038 A 6019970345 SEAL RING 001
    041 A 6010780085 PIPE BRACKET 001
    047 A 6010920040 BRACKET,
    Prefilter 001
    050 N000933006312 SCREW,
    M 6x22 001
    056 A 6050700732 LINE,
    From prefilter to shut-off valve 001
    074 A 6050700832 LINE,
    From shut-off valve to feed pump 001
    081 A 1239950065 CLAMP,
    At feed and return lines 001
    082 A 1159950365 CLAMP,
    At feed and return lines 001
    083 A 6050701032 LINE,
    From feed pump to fuel filter 001
    095 A 6050700632

    Замена:
    A 6050701532
    A
    LINE -
    095 A 6050701532 LINE,
    From fuel filter to shut-off valve 001
    119 A 6050701232 LINE,
    (return line) from injection pump to fuel filter 001
    125 A 6010700646 VALVE,
    (overflow valve) 001
    126 A 0179972248 SEAL RING,
    Fuel line and overflow valve on injection pump 001 006
    128 N007603012102 SEAL RING,
    Fuel line and overflow valve on injection pump,
    12x16-cu 002
    134 A 6010942441 BRACKET,
    Fuel lines to filter 001
    137 N000933006183

    Замена:
    N304017006016
    N
    SCREW -
    137 N304017006016 SCREW,
    Fuel lines to filter,
    M 6x16 002
    140 N000137006204 SPRING WASHER,
    Fuel lines to filter 002
    146 A 6050780281

    Замена:
    A 6050780581
    A
    HOSE -
    146 A 6050780581 HOSE,
    From no.1 nozzle holder to fuel return line,
    340 mm 001
    149 A 6050700055 RUBBER CAP,
    Nozzle holder,
    No.5 001
    155 A 6040700179 HEAT EXCHANGER,
    Fuel thermostat 001
    161 A 6040780180 SEAL,
    Fuel thermostat to cylinder head 001
    164 A 6051590040 BRACKET,
    Fuel thermostat to cylinder head 001
    167 A 6040780171 SCREW,
    Fuel thermostat to cylinder head 002
    167 A 6040780371 SCREW,
    Fuel thermostat to cylinder
     
  18. OP
    rustynuts

    rustynuts Member

    Messages:
    10
    Likes Received:
    0
    Joined:
    Dec 24, 2012
    Your Mercedes:
    C250TD
    spot on , thankyou
     
  19. chizzel89

    chizzel89 Senior Member

    Messages:
    345
    Likes Received:
    0
    Joined:
    Feb 27, 2011
    Location:
    Pembrokeshire
    Your Mercedes:
    Mercedes-Benz C250 Turbodiesel Sport Auto. Estate. 1998. 180,000 mls
    Contact Silversaloon on here for a Viton O-ring kit. The Merc ones don't last too long with biofuels.
     
  20. OP
    rustynuts

    rustynuts Member

    Messages:
    10
    Likes Received:
    0
    Joined:
    Dec 24, 2012
    Your Mercedes:
    C250TD
    thanks to everyone, got it running after sorting the pre filter seal, running a treat now,just off to fill the tank with diesel::)
     

Share This Page