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MG Midget and Sprite Technical - What can it be?

Hi Guys

Still getting problems with the midget I bought at the beginning of October and it's very frustrating - I'm sure you've all been there at sometime or another!

I can run the car for 15-20 minutes then it starts to lose power and die. It will then not start until it's cooled down again - probably about 15 minutes later. The car does not overheat and I've got fuel to the carbs. I've done alot of research in the archives recently and believed the problem was a dodgy coil. Ordered one from Moss and it turned up leaking oil! All credit to them, a quick phonecall and a new one was in the post arriving next morning. However, the new coil hasn't solved the problem.

Help!

Regards

Steve
Steve Osmond

I know this is a standing joke on this BBS, but it could be worth changing the condenser although your 'New' Coil could be at fault, it is not unheard of.....

Mark.
Mark T. Boldry

Mark

Someone I know has suggested the condenser. I think I should have replaced it when I did the coil. The annoying thing is that Moss have a limited order amount and the condenser costs next to nothing! I'll need to buy something else as well then!

Regards

Steve
Steve Osmond

Steve,

Its a fairly standard part - try your local car bits shop or posibly even Halfords !
Or go electronic and forget points and condensers.

Richard.
richard boobier

I had exactly the same symptoms with my Mk3 Midget, and my husband with his Austin A30. Turned out to be the distributor cap! As it got hot, a hairline crack appeared, and closed again when cooled down. A new one, and a new rotor arm, could clear this up!
Margaret Brock

when I began working breakdowns for the AA many years ago
(78 it I believe it was...) a well experienced patrol told me the only way to be sure with ignition systems was to replace evrything inside and outside the dizzy. Points, condenser and rotor arm inside and cap and leads outside.

That was in the days before every patrol carried a multimeter, and for the times was very sound advice.

with the arrival of the personal meter some of those became less significant but cracked injection moulded plastic (rotors and caps) can still be very difficult to trace and condensers did fail even back in those halcyon days when Lucas made their own parts for contact sets and condensers.

What Mark suggests is a possibilty (Rather high chance of it being that) as is cracked plastic

very close inspection and physical pulling and pushing might show cracks in the cap

such cracks can be temporarily plastered over with tippex and I have known "tippex" repairs last for years

even on some rotor arms but less often with HT leakage on them
Bill

Just an outside thought, has the car got a heatshield on the carbs? Or a weak fuel pump? What root does the fuel pipe take?

Shaun
Shaun

I had exactly these symptons, in the end it was that old favourite the rotor arm, which was not old, looked completely perfect and was "genuine" Lucas ! probably made in India/Taiwan etc!

I now have purchased two much better quality from the Distributor Doctor website, expensive but good.
Here is the explanation they give of what happens with dodgy rotor arms:

Recently manufactured rotor arms have been failing because the typical "mix" used in the injection moulding nowadays contains more carbon blacking and is therefore more conductive. Still more importantly, the rivet which holds the brass inlay into the moulding is slightly longer than the original, bringing it too close to the spring clip on the underside. The high tension current, averaging 30,000 volts, is always looking for the easiest route to earth and shorts out from the tip of the overlength rivet, through the reduced thickness of more conductive plastic and the spring clip on the underside of the rotor arm, to earth out down the distributor shaft. Result - no sparks at the plugs. The situation sometimes rectifies itself on cooling, but then reoccurs with increasing frequency until the rotor permanently short circuits.

Ian
Ian Webb '73 GAN5

Or if everything mentioned above check if there is a bad vent at the fuelcap side. You will see fuel at the carbs but its not moving anymore. Easy to check, put a piece of plastic instad of the fillercap attached with a rubber band and pierce a hole. If venting was a problem and it isnt anymore its the cap.

Check for cracks in the rubber washer inside the cap. If its cracked it expands while screwing it on the fillerneck and blocking the vent holes. But my first guess would be electrics
Bas Timmermans

Sounds like a rotor arm, i changed mine at a service & it lasted for all of 5 miles. That was from Halfords.
Bought a new dizzy cap & rotor arm from Aldon & no problems in the last 4 years.
Brad
Brad (Sprite IV 1380)

Also, for parts, try sussexclassiccar.co.uk. They are lovely, helpful and very reasonable on prices. Much nicer to deal with than Moss who drive me up the wall.
Rich Amos (1 Sprite 1 Midget!)

I had a simular problem long ago and the car would run for a couple of miles then suddenly act like it was out of gas but it turned out there was no spark. After hours of trying everything I could think of I tried a hot wire to the coil and the car started right up. Turned out to be a bad ground inside the distributor on the plate that the points and condenser screw down to. I used a hot wire with a switch till I could get a new distributor in. Have no idea if this helps but its easy to test anyways.
P Ruszczyk

Steve,

It's a long shot, but I had a similar problem with a truck that had a rubber hose for the full run from the fuel tank to the engine mounted fuel pump. On occasion, the suction would collapse the hose. After sitting a bit it would loose the suction and start up like normal.

Charley
C R Huff

Dont just buy one condenser...buy 5 to 7 of the little critters....there should be at least one good one in the batch

Really I am appalled at you guys critizing asian made autoparts....if your 7 year old daughter had dropped out of school and worked 16 hour days making parts for 10 cents a day, ....I bet you would be so much more loving to the asian all under 12 years old ALL girl manufactureing base....LOL

God I love being an american...hypocrosy and aerogence just feels so good with a cup of hot choclate on a saterday morning...LOL


prop
Prop


Very long shot, but I once had a pinhole in the top hose. Car would run fine till it got hot and the thermostat opened, then a fine jet of water from the pinhole hit the distributor and stopped the engine!

While the car cooled down till it was ready to restart, the cause of the problem evaporated!

Took a lot of head scratching to solve that one.

Andy
a borris

how about giving it a full service
Alex Sturgeon

Guys

Thanks for all the advice. Someone with alot more knowledge on the subject came around on Sunday to have a look into the problem with me. I'm sorry this is so long winded but I want to give you as much info as possible.

Both times previously when the car has broken down I have taken exactly the same route and it has done it a virtually the same place.

My friend went down the filler cap route. The filler cap is a very tight fit and the only place we could see it was possible to vent was through the keyhole. However, it appeared that this wasn't possible as we weren't able to blow through it. We got the car started and warmed it up although we didn't put the cap on until I took it out for a run meaning. The car ran really well - I did the same route and the car did not break down and then went further with no failure. It wasn't until I was reversing the car into the garage that the car finally spluttered and died.
My friend took the filler cap off and asked me to try to start the car but it failed to start. On popping the bonnet open the fuel filter just before the carbs was empty.

My friend reckons I've got a faulty fuel pump. However, I'm not so sure. When I've broken down on the previous two occasions there has been fuel in that filter. Surely the car would be playing up all the time? BTW, it's a Midget Mk1 with a mechanical pump.

I actually believe the fault is linked to the car getting up to full running temperature and a component failing and the reason it took so long the other day was that it was much colder and took alot longer to get up to that temperature.However, why do you think there was no fuel visible in the filter on this occasion?

Any more ideas and thoughts greatly appreciated!


Regards

Stevde
Steve Osmond

Steve,

i'd go with a weak pump, just had the same thing on my 'other' classic.
The one with 6 cylinders :-)

Brad
Brad (Sprite IV 1380)

Agree with Brad, I would fit a facet pump to remove the old pump from the likely contender list
Alex Sturgeon

I had similar intermittent problems with a mechanical pump on my 1500, some years ago. Eventually tracked it down to a small split in the pump diaphragm. It still allowed it to pump but would gradually "loose pace" with the engine until the engine began to cough and splutter. Nursing it along at low revs allowed the pump to "catch up" again. Replaced the diaphragm and all was well again. Easy to check by removing the pump cover.
Guy Weller

Tippex isn't what it was Bill,

Apparently they changed the formula due to the previous stuff ripping great holes in the ozone layer.

In any case, it makes a terrible mess on the monitor screen when you are correcting the typing.

Dave.
Penwithian

Ah

I must be using old stock (maybe even knock off but perish the possibility...)

The old stuff (proper Tipppex not some of these modern interlopers) was actually a sort of matt surfaced plastic

saved the world for many a poor soul

and now THEY are saying it doesnt save the world!

what a sad place we are these days

I wonder what Doctor David Bellamy thinks about the demise of Tippexery, he is at least as big a "Global Warming Sceptic" as I am
Bill

I have had to replace condensers in the last year, i now carry a spare with me at all time. The last time I was on my way into work and had to replace same while stopped on a bridge.It only takes a few minutes Declan
D M McGinley

I agree this can be frustrating. My daily driver, a '98 GTI VR6, has reached something like 80K miles with only minimal service. But with the Midget, I've found myself replacing parts that are by no means original to the car; in some cases they're components that I installed myself only a few years ago, and they've already failed. an Indian-made front wheel bearing comes to mind.

-:G:-
Gryf Ketcherside

Bill there is certainly a lot of confusion in the world as our earth is a very instable planet that small changes to result in big events.

I think it is fair to say that most of us use the term global warming simply to describe what will happen to our world if we continue to place MILLIONS of tonnes of polutants into our finite atmosphere. It may overheat the planet as has happened before or it may freeze the planet which also has occured many times over the billions of years of earth's evolution. I can not believe that some people do not think that poluting our atmosphere will have no effect. Surely most of us older generation will remember the terrible local smogs we used to have when just we in the UK had coal fires!! Fortunately we overcame that local polution effect with a little bit of technoledgy and commonsense, we simply now need to do the same again with global polution. Do you disagree with that synopsis Bill?
Bob (Robert) Midget Turbo

Jesus saves!
The end of the world is nigh!
Bob's finally flipped!
;-)
David Smith

For God's sake be careful with the Tippex.

Dave
Penwithian

This thread was discussed between 08/11/2008 and 14/11/2008

MG Midget and Sprite Technical index

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