Section : Fuel and Additives

Help ! a GT6 rookie needs you 

Posted By : Christopher Barrand, 04-May-2006, 06:42am

• Help ! a GT6 rookie needs you 

  Posted By : Jonathan Binnington, 04-May-2006, 07:34am

  have a really close look at the pipes from the tank to the petrol pump and thence to the carbs, i wonder whether the problem isn't with the tank ata all but between the pump and the carbs or with the carbs themselves
  
  j

  • Help ! a GT6 rookie needs you 

    Posted By : John Davies, 04-May-2006, 11:41am

    Chris,
    "discharging under the rear"
    Foregoing the territory marking joke, have you seen fuel dripping out of this pipe?
    The tank needs a breather to allow air in as fuel is used up. It shouldn't let fuel out that way.
    Mk1s had a breather on the front, inside corner of the tank itself that drained onto the ground.
    Later Mks had breathers from the sensor unit to the filler pipe and from there to the ground.
    Does it happen only when the tank is full, or any time?
    The GT6 tank is low in the body - if there is a small leak forward, say at the fuel pump on the engine, then fuel in the supply pipe could track back into the tank and overflow it.
    
    Suggest you start up with the bonnet open and someone to watch the pump and carbs for leaks and someone else watching under the car for drips.
    Then watch again after turning off - in case it's happening as above.
    Newspaper under the car can be a useful marker for where slow drips are - unless you have to park in the open.
    
    John
    

    • Help ! a GT6 rookie needs you 

      Posted By : Geoffrey Griffiths, 04-May-2006, 12:25pm

      Hi Chris
      I have a Mk1 also and also get a smell of petrol both in the car and garage after it's been parked up after a run. There are sveral possibilities not least of which is a slight leak from the carbs via the throttle spindles. If the carbs have not been overhauled they can leak from quite a few places. the idea from John to place some newspaper under the car when parked is reasonable in finding a leak which is dripping. A leak which is just weeping will probably evaporate before you see it.....but it will give a very strong smell of petrol. The most obvious area I believe is the vent from the tank. This is an open pipe (rubber) which as you say vents through the nearside rear floor alongside the wing. It is supposed to be sealed with a rubber grommet to prevent vapour entering the cabin. Most likely the grommet is perished or not present allowing the fumes to percolate into the cabin when parked. It's strange that part of the MOT test is to examine the seal between the petrol filler cap and the filling pipe. I presume this is a safety device to stop fumes entering the vehicle or an emissions issue (neat fumes entering the atmosphere) If it's the latter then they coveniently ignore the vent pipe. You can replace the rubber grommet easily (which I have not done yet) from the outside. You can also seal the vent temporarily and see if the smell goes away....there should be enough leak past the petrol cap to prevent a partial vacuum developing in the tank. Also look at the large rubber connecting pipe from the filler cap to the tank and check the 2 jubilee hose clips for tightness.
      Good luck
      
      Geoff

      • Help ! a GT6 rookie needs you 

        Posted By : Colin Lindsay, 04-May-2006, 02:09pm

        I reckon they all smell of petrol, sort of a period 1960s thing... unless there's a definite leak then as discussed I'd agree it's the breather.
        Colin

        • Help ! a GT6 rookie needs you 

          Posted By : Nigel Gibbins, 04-May-2006, 03:24pm

          Another thought (which was certainly the case on my MK1) was the petrol tank sender unit.
          
          It is possible the seal is not as good as it used to be and your fumes are coming out of this. I used to find that after filling up, under hard braking then petrol actually came out of the sender (hole) and then dripped out through the boot floor. This also caused a stink
          
          If this isn't it then I would expect a perished (or perishing) pipe somewhere... you should check for signs of weeping or cracks at all the joints.

• Help ! a GT6 rookie needs you 

  Posted By : George Ralph, 04-May-2006, 04:23pm

  I have a MK1 (modified), it stinks of petrol, hot oil, exhaust gasses and boils my feet. If I had any hearing left, it would deafen me too! Like someone said, it's a sixties thing, for my part, I'm fifties vintage, so I see it as pure petrolhead heaven!
  
  My everyday car (F*rd C**gar Coupe and boring as hell) starts every time, smells of leather and just cost me &163;190 for a years tax, 'cos it's the same as a "Chelsea Tractor" according to our Gordon, even though I live in Dorset where we know what real tractors look like!
  
  Seriously, it is too easy to think you have a big problem when dealing with classic cars, especially when new to the game and with your "modern car" head on. I have noticed that modern unleaded seems to evaporate much quicker than old style petrol and has a particularly pungent smell in an enclosed garage 9just a gallon of chemicals really). The MK1 has a 3/8 inch vent pipe from the tank (with no valve) as you have noticed and if the tank is fairly full in a garage then the smell of unleaded can be very noticeable.
  
  Like everyone said, check all the fuel lines for integrity. Then start her up, open the window and just listen to the awesome sound of that "six".
  
  Cheers George

  • Help ! a GT6 rookie needs you 

    Posted By : Van Hamlin, 04-May-2006, 04:54pm

    Chris's car should not smell of petrol. Mine doesn't, and the only times in the past when it has I have found a leak. Why are people posting messages saying this smell is normal? If Chris's car catches fire then some people are going to look a right bunch of idiots aren't they.
    
    A number of leak points have already been mentioned from the more constructive posters but the fuel pump also can leak from a number of places - the top bolt, the sealing ring between the two halves, and least noticeably but very significantly the priming lever - look and feel underneath.
    
    But if the smell is very strong and during starting I would think the carbs are flooding. Take the air filters off and have a look. If a carb piston is not going down as far as it should then excessive fuel will be pumped up the jet and can pour out. This can be caused by grit or damage in the jet. The carbs can also leak from the bottom around the jet attachment, but this is more of a slow trickle and is constant rather than just when starting.
    
    Van
    

    • Help ! a GT6 rookie needs you 

      Posted By : Jason Chinn, 04-May-2006, 05:00pm

      Be gentle Van, if your car had always smelt of petrol and you'd not found a leak you might assume it should smell like that! Personally I would adopt the attitude that it should not smell of fluids that should normally be contained, on account of the fact that they smell and are inflammable. I don't think the car buying public of the 60s just accepted that kind of thing when the cars were new so I wouldn't accept it now. Leaking fuel is not a good thing. Work carefully through the fuel system and check for leaks, including the filler cap - the one on my Vitesse (and the Herald before it) is a pain and leaks on right hard cornering or any right cornering when full! It's a locking cap and probably needs replacing.

      • Help ! a GT6 rookie needs you 

        Posted By : Jonathan Binnington, 04-May-2006, 06:07pm

        got it... it's the tank vent, pipe perished or missing, remember my gt6 used to also smell of fossil distillates until i replaced the split vent pipe to the great outdoors
        
        j

      • Help ! a GT6 rookie needs you 

        Posted By : Jonathan Reed, 04-May-2006, 07:57pm

        Jason,
        
        After leaving the original filler cap on the boot and depositing it somewhere on the A47, I replaced it with a plastic lockable (leaked), US import shiny metal replica (leaked). Finally bought a NOS Stanpart off ebay, not much shy of &163;20, but a a perfect seal! A bargain in disguise!

        • Help ! a GT6 rookie needs you 

          Posted By : Jason Chinn, 04-May-2006, 10:29pm

          I've experienced some of those upgrades before - you buy new coz you think it's better and end up looking for NOS or good second hand because it's the best!

    • Help ! a GT6 rookie needs you 

      Posted By : Colin Lindsay, 04-May-2006, 05:58pm

      Sorry to be an idiot Van but if Chris states that his car, WHEN STARTING smells of petrol then I assume that's normal for a car on Stromberg carbs starting on the choke.
      At no point is a leak mentioned, nor does he state that this is while driving, or persists for any length of time.
      If Chris is really a GT6 rookie coming from more modern cares then engine smells might seem quite strong compared to no smell at all with a Eurobox.
      If there is a leak then rather than looking for one himself I suggest he gets the car professionally checked over. Happy?
      Colin

      • Help ! a GT6 rookie needs you 

        Posted By : Chris Taylor, 05-May-2006, 02:23pm

        Other possible sources of leaks/fumes:
        
        The O rings in the base of Stromberg carbs can perish and allow fuel to leak out. Alarming with the close proximity of the exhaust manifold......................
        
        Check the integrity of the pipe connecting the filler cap to the tank. The (very short) pipe stub on my Vitesse tank corroded where it passes through the rubber grommet in the wing (= rear panel on GT6) and caused fuel to spill out when the tank was full and fill the inside of the car with fumes.

• Thanks from the GT6 rookie 

  Posted By : Christopher Barrand, 07-May-2006, 08:09pm

  
  Thanks to you all for your help on tracking down the smell of petrol.
  I serched high and low for the leak and it was only found when I filled up at the garage, petrol was dripping from below the car from the hose connecting the tank and filler cap.
  Whenever I went out in the car my drive is on an incline which caused the fuel to escape, but only when going up a steep hill.
  Thanks again