Classic cars forum & vehicle restoration.

Finch661 · Posted: Thu Oct 22, 2009 1:43 pm Post subject:

thats an intersting one. i have replaced the leads, though im sure i bought them from mgocspares.com, i have noticed that my exhaust is petrolly smelling. i will have a look in the dark to see if i get any blue glow from plugs, leads and coil. is there any way of testing if the spark is strong?
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1985 Mini Mayfare (1275)
1976 Mg Midget 1500

victor 101 · Joined: 03 Apr 2009 Posts: 446 Location: East Yorkshire

You should be able to get a spark tester at Halfords or your local motor factors, they are only a couple of bits of plastic hinged at one end and a couple of metal bits in the middle, you just move the two pieces closer together and when the spark jumps the contacts you look where the pointer is and it will tell you the strength of your spark.

Finch661 · Posted: Wed Mar 10, 2010 1:50 pm Post subject:

afternoon all, i am reopening this thread, as i am still getting really bad mpg (still 20mpg). i gave the car a quick run and checked the plugs, and they were a browny colour, so it looks like the mixture is right. i have bought two second hand HS4 carbs in good nick, so i will fit these and see if that helps

if it is a case of bad carbs, what could it be in the carbs that causes bad mpg?
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1985 Mini Mayfare (1275)
1976 Mg Midget 1500

mid · Joined: 10 Jun 2008 Posts: 136 Location: Northampton

my midget was suffering from bad economy... turned out to be the flexy hose from the fuel tank to the pump was split, not enough to leak when stationary but when running i was loosing loads! only noticed it when i noticed that some of the underseal was abit soggy underneath.

mines a 1275 so not sure of the pump set up on a 1500?

Jim.Walker · Joined: 27 Dec 2008 Posts: 1229 Location: Chesterfield

Silly question this, but I have known it to be significant in fuel consumption problems. Have you checked that you have no binding brakes? Even when undetectable in normal driving the effect of a binding brake can be very significant.

Obviously, the correct needles and springs in the carbs. are essential. There is no need to consult a mechanic. Everything you need to know should be listed on here. Along with prices and availability of parts.

http://www.sucarb.co.uk/CompanyProfile.aspx

Jim.
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Quote from my late Dad:- You only need a woman and a car and you have all the problems you
are ever likely to want". Computers had not been invented then!

baconsdozen · Joined: 03 Dec 2007 Posts: 1119 Location: Under the car.

A good point,binding brakes and/or low tyre pressures will knock MPG as well as a sticking choke or even a cold running engine.
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Thirty years selling imperial hand tools for old machinery(Now happily retired).

Finch661 · Posted: Fri May 14, 2010 4:19 pm Post subject:

hi folks thanks again for all the replies. all the brakes are fine, they move very freely. i have checked the pump, all the fuel lines have been replaced, but still its getting poor mpg. i have bought a pair of refurbed carbs, so i will see how these do!
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1985 Mini Mayfare (1275)
1976 Mg Midget 1500

Jim.Walker · Joined: 27 Dec 2008 Posts: 1229 Location: Chesterfield

"The nut that holdes the wheel" can have a significant effect on fuel consumption. Any excessive acceleration or speed are obvious wasters, so why do people continue to accelerate when it is obvious that stopping is imminent? All the petrol used to get to that speed is "thrown away" every time the brakes are used! I am amazed at the number of drivers who pass me in the next lane as I am gently losing speed because the lights in front are red. Then they compound their waste of fuel by accelerating and braking hard at the next set of lights which can obviously be going on red before they get there.
Excessive braking is as bad as excessive acceleration and hanging on to lower gears is also wasting fuel. It is not always the car or carbs at fault.
_________________
Quote from my late Dad:- You only need a woman and a car and you have all the problems you
are ever likely to want". Computers had not been invented then!

Finch661 · Posted: Tue May 18, 2010 1:30 pm Post subject:

totally agree with you Jim, the number of people i see flooring it, only to stop about 20m later, its daft. i granny drive my cars now, especially the mg.

so far i have replaced:
the carbs (recons, with correct needle)
ignition system (sparks, ht, dizzy, upgraded to electronic ignition, coil)
fuel tank and main pipe

could an old fuel pump leak fuel into the oil?
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1985 Mini Mayfare (1275)
1976 Mg Midget 1500

victor 101 · Joined: 03 Apr 2009 Posts: 446 Location: East Yorkshire

A mechanical fuel pump working off a camshaft could leak fuel into the block and into your oil.

Finch661 · Posted: Tue May 18, 2010 2:15 pm Post subject:

are there anyways of checking if a fuel pump is leaking into the block? its a standard mechanical pump as fitted to the mg midget
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1985 Mini Mayfare (1275)
1976 Mg Midget 1500

victor 101 · Joined: 03 Apr 2009 Posts: 446 Location: East Yorkshire

Easiest way is undo the bolts holding the pump and tilt it forward, but if it was leaking bad I would expect it to be noticable in your oil.

Finch661 · Posted: Tue May 18, 2010 2:54 pm Post subject:

i will have a look tonight. the oil did smell petrolly, but i assumed that was normal wear and tear?

will keep you posted!
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1985 Mini Mayfare (1275)
1976 Mg Midget 1500

Finch661 · Posted: Thu Oct 28, 2010 9:53 am Post subject:

hey ho folks, still no improvement on the car! i have fitted two refurbed (new jets, needles, floats, neelde valve, throttle plates) carbs to the midget, and guess what...still the same consumption.

Sad

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1985 Mini Mayfare (1275)
1976 Mg Midget 1500

Jim.Walker · Joined: 27 Dec 2008 Posts: 1229 Location: Chesterfield