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MG Midget and Sprite Technical - Well it never rains it pours!!!

Hi there!!!

Having had nearly six months of trouble free motoring since my last brake issues it was time something went wrong with my midget. Now it seems I've had three issues develop in three days and I've only fixed one!! Firstly it started running on two cylinders... Checked and replaced plugs plus did the rotor arm and cap whilst I was at it. No good. Double check gaskets around inlet manifold with carb cleaner - AHA! Leaky gasket at intake manifold. Fixed. Day goes by of trouble free motoring.

Now the car has developed a problem whereby intermittently it goes down on power (I think still four cylinders firing) to the extent it stalls and feels very asthmatic unable to rev above 3k. Compression check I did showed good even compression around 135-145 psi. Only things I can think to check now really would be replace the condenser (perhaps heat related?), check there is fuel in the float when it's cutting out - if not I'll check the fuel filter and the fuel tank filler cap... anything else anyone can think of...?

Then when trying to pinpoint my engine woes on a short test drive, the brake pedal goes to the floor. Not again I think after some pumping brake pressure returns (hmm... must be an air leak - I only renewed the master cylinder six months ago). Then the pedal continues to work for a while until the sponginess fades in and out from time to time. No signs of fluid from M/C all the way to each brake and the front and rear unions, rear is *slightly* out of balance which may explain some sponginess but not to this extent. Alas, I'll bleed these tomorrow and see what happens (still doesn't get me to the root cause of the presumed air leak!)

Anyone got any ideas on either the current engine troubles or what might cause the brake issue!!!?

Cheers,
Josh
J Emerson

Josh,
When the car intermittently goes down on power, does the rev counter needle jump around erratically? Assuming its an electronic rev counter this would pin-point the fault as electrical, rather than fuel related.

If the needle is reasonably steady, although falling, then the problem is likely to be fuel related.
Guy W

Hi guy, The needle is falling at a reasonably steady rate and not particularly erratic unless I'm revving the engine and adding choke to sustain the engine (which helps, but eventually proves no use and it will just splutter to a halt).

I'll also try to get a video clip tomorrow which may help!
J Emerson

Sounds to me as if you have a lump of detritus trapped in the fuel jet (I don't mean the float chamber fuel inlet). This is inhibiting fuel supply, but is pushed clear when the needle drops down into the jet which is why it appears to run fine at times, and then starts to cough and splutter.
Guy W

X2 guy

Also clogged tube from float to the jet....if you have to pull the xhoke to keep it running....classic example

Spray can carb cleaner with the thin straw tube....pull the jet off the bottom of the carb and stick straw into the jet hole on the jet tube and spray and work it thur

But do check the float 1st to make sure its funtioning fine

Prop
Prop and the Blackhole Midget

Thanks for your help guys pretty much bang on in terms of fuel blockage.

Brakes still seem spongy despite bleeding so I'll have to get the MC out sometime this weekend and check it :)
J Emerson

Josh,
when you changed the MC did you also check (or change) the flex-hoses

if you not already done so adding in a cheap (89p) disposable fuel filter just before the carbs as this will help not only filter the fuel but also make it easy to see if the fuel has made it as far as the filter at least, change it annually/12k-miles

if you wanted to, it might be useful if you added your 'view vehicle profile' with details of the model and year and any extras added (servo perhaps) as the models did have many changes over the years and the profile can sometimes cut confusion or wrong questions or answers
Nigel Atkins


Have alook under the dust caps on the rear cylinders. It could be a leak there.

When I had this issue it was the M/C though.
Gavin Rowles

Josh,

I had a similar problem a few years back with my brakes. Bad machine work on the master cylinder bore. Had to replace two before I got a good one. Moss/Lockheed finally admitted they had a problem. Got pretty good at changing them out though.

Regards,

Larry C.
Larry C '69 Midget

This thread was discussed between 05/11/2012 and 09/11/2012

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