Very bad fuel consumption
  • Register
  • Help
Results 1 to 16 of 16
  1. #1
    Member amremarah's Avatar
    Join Date
    Apr 2005
    Location
    Cairo / Egypt
    Posts
    118

    Default Very bad fuel consumption

    Hi fellow froggers

    Advertisement


    As you all know I'm in the process of restoring my 504 and I'm almost done..
    a strange thing I realized in the first step in my restoration is that after installing power steering, electronic ignition and a full clean of the carby ( my mechanic changed the speed valve cause he told me that it was worn, its no. was 38.5 but didn't find the no. and instead intalled the 37 ) I cruised with the car for about a week..going to work, downtown and family stuff and noticed lose of fuel very fast or as I assumed cause it was difficult to measure it due to different driving conditions, when I went to my mechanic again for secound step ( Suspension setup ) I told him about this problem and at the end of the work he told that he reconfigured and tuned the carburator.
    last week took a trip with my family to Alexandria ( 260 km from Cairo ) and here was the big SHOCK!!!! the car took exactly 45L /260km
    last year I took this trip 25L /260km, so what am I facing here!!!?
    PLEASE HELP
    1975 504GL

  2. #2
    Fellow Frogger! Decca's Avatar
    Join Date
    Jul 2004
    Location
    Canberra
    Posts
    896

    Default

    That consumption reminds me of a Chrysler Valiant that I owned very briefly.

    I dont understand the speed valve part but some carby guru may reply later.

    I'd check for leaks in the whole system ( dont forget the fuel filler cap).
    check the exhaust pipe after a good run. it should be greyish and dry if the fuel mixture is right .
    Black smoke coming out of the exhaust when you are driving hard is unburnt petrol


    Decca
    Present --2016 2008 Outdoor / 2014 RAV4 Diesel (My utilitarian beast)

    Past -- 19?? 403 / 1974 504GL / 1972 R12TL / 1995 405SRi / 1997 406ST / 1998 306XT / 2004 406HD1 / 2008 308XSE HDi / 2008 307XSE

  3. #3
    1000+ Posts Gamma's Avatar
    Join Date
    Oct 2004
    Location
    Picton NSW
    Posts
    1,412

    Default

    By speed valve do you mean jet size.

    Under jetting a carby can affect the fuel comsumption just as badly as over jetting.

    Get a gas analysis to determine the CO and Hydrocarbon content and jet accordingly.

    Calling all Webber/Solex experts. Is the jet fixed or can it be adjusted or adjuster fitted as per Stromberg.
    /// 1986 SII 505 GTI
    2003 T5 307 HDI
    2013 LandRover90
    Sacred cows make the best hamburger mince.
    If you run, you only die tired

  4. #4
    Fellow Frogger! James504's Avatar
    Join Date
    Jul 2004
    Location
    Brisbane
    Posts
    803

    Default

    My 504 gets 5.5ks to the litre. And you think yours is shocking. Even after i fixed the fuel pump leak. But it is a 3 speed auto, and the use of my right foot may be a little excessive.
    2006 Peugeot 206 Xt
    1991 Toyota mx83 grande 1jzgte

  5. #5
    Fellow Frogger! 123abc's Avatar
    Join Date
    Feb 2005
    Location
    brisbane
    Posts
    358

    Default

    this is sounding like a choke problem or accelerator pump problem......

    its an honest mistake to forget to check the accelerator pump because when it is stuffed it sometimes will constantly squirt fuel into the throat.....and so it gives the illusion that it is working because the car wont snuff when you put your foot down.

    (other times when its stuffed it wont let any fuel through at all, and so the car will snuff all the time)

    take the air cleaner hose off and shine a torch down the throat and look for fuel, if you see drops or squirts of fuel then that is a problem, it should be a mist....

    check the tank itself for leaks to, i had a leaky tank which was anoying...

    check timing too

  6. #6
    Member amremarah's Avatar
    Join Date
    Apr 2005
    Location
    Cairo / Egypt
    Posts
    118

    Default

    Quote Originally Posted by 123abc
    this is sounding like a choke problem or accelerator pump problem......

    its an honest mistake to forget to check the accelerator pump because when it is stuffed it sometimes will constantly squirt fuel into the throat.....and so it gives the illusion that it is working because the car wont snuff when you put your foot down.

    (other times when its stuffed it wont let any fuel through at all, and so the car will snuff all the time)

    take the air cleaner hose off and shine a torch down the throat and look for fuel, if you see drops or squirts of fuel then that is a problem, it should be a mist....

    check the tank itself for leaks to, i had a leaky tank which was anoying...

    check timing too
    I don't think I have a leaking tank cause if I park the car for 3 or 4 days the fuel level is the same
    well I'll go under the bonet today to see any leaks from the pump, filter and also what you mentioned but I think if there is a leak I'll smell it
    also this only happened just after changing the speed valve from 38.5 to 37 ( it is a very small copper cylinder with a tiny hole in it alowing fuel to pass through it, the number on the worn part was 38.5 but I didn't find it so it was replaced with 37 or 36 ( don't remember )
    thanks
    Amr
    1975 504GL

  7. #7
    Member amremarah's Avatar
    Join Date
    Apr 2005
    Location
    Cairo / Egypt
    Posts
    118

    Default

    Sorry guys for the mis-information
    I mean by speed valve the JETS
    and it was 138.5 and changed to 136
    Amr
    1975 504GL

  8. #8
    1000+ Posts Wildebeest's Avatar
    Join Date
    Oct 2004
    Location
    Perth Western Australia
    Posts
    2,694

    Default Fuel consumption.

    Quote Originally Posted by amremarah
    Sorry guys for the mis-information
    I mean by speed valve the JETS
    and it was 138.5 and changed to 136
    Amr
    Amr,
    Details before me. For a Solex 32/35 SEIEA.
    Primary jet=125. Secondary jet=137.
    Has your mechanic fitted the jets arse about?
    Get him to check if the choke butterfly/s are coming right off when warm.
    How's your air filter? A bit dusty over your way I'm told.

  9. #9
    Member amremarah's Avatar
    Join Date
    Apr 2005
    Location
    Cairo / Egypt
    Posts
    118

    Default

    Quote Originally Posted by Wildebeest
    Amr,
    Details before me. For a Solex 32/35 SEIEA.
    Primary jet=125. Secondary jet=137.
    Has your mechanic fitted the jets arse about?
    Get him to check if the choke butterfly/s are coming right off when warm.
    How's your air filter? A bit dusty over your way I'm told.
    I'm not sure about the sizes but I'll let the mechanic check it again
    What is the chocke butterfly?
    I'll also check my air filter
    Thanks for the tips matt
    Amr
    1975 504GL

  10. #10
    Member amremarah's Avatar
    Join Date
    Apr 2005
    Location
    Cairo / Egypt
    Posts
    118

    Default

    Forgot to mention something!!
    I realized when trying to reach 120km/h ( 4500 rpm ) the engine makes strange cut offs ( like disconnecting fuel from the engine for a secound and then back on ) so I just stick to 110 - 115 km/h
    Is this a carby problem or engine
    Hope you understand
    Amr
    1975 504GL

  11. #11
    1000+ Posts Wildebeest's Avatar
    Join Date
    Oct 2004
    Location
    Perth Western Australia
    Posts
    2,694

    Default Fuel consumption.

    Amr,
    The choke butterflies are the two flaps that close over the top of the carb when choke is on for cold starting. It is operated either manually or automatic. If they are stuck partially on your consumption will increase.

    The other problem, your 504 hesitating at 120 kph. If it is a short sharp cut out it could be spark plugs, leads or the insulators in the spark plug tubes.
    If it is a gradual hesitating it could be a fuel blockage in the tank, fuel lines,
    fuel filter or within the carby.

  12. #12
    Member amremarah's Avatar
    Join Date
    Apr 2005
    Location
    Cairo / Egypt
    Posts
    118

    Default

    Quote Originally Posted by Wildebeest
    Amr,
    The choke butterflies are the two flaps that close over the top of the carb when choke is on for cold starting. It is operated either manually or automatic. If they are stuck partially on your consumption will increase.

    The other problem, your 504 hesitating at 120 kph. If it is a short sharp cut out it could be spark plugs, leads or the insulators in the spark plug tubes.
    If it is a gradual hesitating it could be a fuel blockage in the tank, fuel lines,
    fuel filter or within the carby.
    for the hesitating prob. yes its a short sharp cut out...but I have changed leads and spark plug tubes with geniune original parts, concerning the spark plugs I also have changed them but can't remember their manufacturer..I think they aren't well known, gues I'll check these sparks...do you recomend installing 4 head spark plugs?
    Amr
    1975 504GL

  13. #13
    1000+ Posts Wildebeest's Avatar
    Join Date
    Oct 2004
    Location
    Perth Western Australia
    Posts
    2,694

    Default Fuel consumption etc.

    Quote Originally Posted by amremarah
    for the hesitating prob. yes its a short sharp cut out...but I have changed leads and spark plug tubes with geniune original parts, concerning the spark plugs I also have changed them but can't remember their manufacturer..I think they aren't well known, gues I'll check these sparks...do you recomend installing 4 head spark plugs?
    Amr
    Amr,
    I wouldn't recommend "4 head spark plugs". It's a bit like having caviar when fish and chips will do! Save them for when you buy your Ferrari.
    Just go for the well known brands and their specification for the 504. Don't use resistor type plugs, these along with your new resistance type leads? may just be arguably too much. If the plug leads still use the wire coil along with the attached resistor this will add up. You will need a bolt of lightning to find its way to the plug

    Amr, you haven't mentioned what type of carburettor your 504 has?

  14. #14
    Member amremarah's Avatar
    Join Date
    Apr 2005
    Location
    Cairo / Egypt
    Posts
    118

    Default

    Quote Originally Posted by Wildebeest
    Amr,
    I wouldn't recommend "4 head spark plugs". It's a bit like having caviar when fish and chips will do! Save them for when you buy your Ferrari.
    Just go for the well known brands and their specification for the 504. Don't use resistor type plugs, these along with your new resistance type leads? may just be arguably too much. If the plug leads still use the wire coil along with the attached resistor this will add up. You will need a bolt of lightning to find its way to the plug

    Amr, you haven't mentioned what type of carburettor your 504 has?
    Wilde
    How can I differ a resistor type plug and a none?
    What do you mean by " If the plug leads still use the wire coil along with the attached resistor "
    I had the carb's part no.before I'll check it again
    Thanks matt
    Amr
    1975 504GL

  15. #15
    1000+ Posts Wildebeest's Avatar
    Join Date
    Oct 2004
    Location
    Perth Western Australia
    Posts
    2,694

    Default Consumption etc

    Quote Originally Posted by amremarah
    Wilde
    How can I differ a resistor type plug and a none?
    What do you mean by " If the plug leads still use the wire coil along with the attached resistor "
    I had the carb's part no.before I'll check it again
    Thanks matt
    Amr
    Amr,
    I believe most resistor type plugs will have an "R" in the type number. An example= Champion N9Y CR.
    Don't worry about the wire coil with resistor , they were used on earlier models.
    I've got something bubbling around in my head regarding your carby and I'm needing to know the maker,ie Solex, Weber or Zenith.

    Amr. I'm very flattered that you call me "matt". I'm simply "wilde or 'beest".
    Matt is a far wiser sage than I'll ever aspire to.

  16. #16
    Member amremarah's Avatar
    Join Date
    Apr 2005
    Location
    Cairo / Egypt
    Posts
    118

    Default

    Quote Originally Posted by Wildebeest
    Amr,
    I believe most resistor type plugs will have an "R" in the type number. An example= Champion N9Y CR.
    Don't worry about the wire coil with resistor , they were used on earlier models.
    I've got something bubbling around in my head regarding your carby and I'm needing to know the maker,ie Solex, Weber or Zenith.

    Amr. I'm very flattered that you call me "matt". I'm simply "wilde or 'beest".
    Matt is a far wiser sage than I'll ever aspire to.
    Wilde
    Found it....ya just as you mentioned its a Solex 32/35 SEIEA 2
    hope the bubles come out with a good explanation
    Amr
    1975 504GL

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •