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Strange problem mg midget 1500

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Mavrick Avatar
Mavrick Jan Jacobs
Brugge, West vlaanderen, Belgium   BEL
Well I tried everything today new spark plugs, set the timing again, set the rockers, fuel pump is working, alternator is working fine, earth strap is connected, engine starts but sputters at 200 rpm when I push the throttle she stumbles and sputters until the engine is hot then she runs oke, then after cooling down same problem. I Really have no clue. Tomorrow I will check the stromberg caburator!

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CountBasey Avatar
CountBasey Thomas Basey
Brunswick, OH, USA   USA
1976 MG Midget 1500 "Opus"
Please post what you find. I'm still running the Stromberg on mine and would like to know.



Thomas (Count) Basey
Member of Emerald Necklace MG Register - www.mgcleveland.com
________________________________________________________

“With each replacement of parts, my British car slowly becomes Chinese.”

Mavrick Avatar
Mavrick Jan Jacobs
Brugge, West vlaanderen, Belgium   BEL
So I tried everything today, new spark plugs, set the rockers, set the timing, ground strap checked, engine started but stumbles and sputters at 200 rpm when I push the gas pedal she sputters and a squeaking sound comes from somewhere, when the engine is hot she run Better, then when the engine is back cool and I want to start some problem over again. Tomorrow I will dismantle the stromberg carburettor in the hope this will be the problem.

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Sarge101st Avatar
Sarge101st Silver Member Brian S
Carlisle, PA, USA   USA
1977 Triumph Spitfire 1500 "Biggles"
1979 MG Midget 1500 "Grrr"
1980 MG MGB "Piddles"
Oh, my, I forgot about the Stromberg.

Before taking the whole carb apart, gently unscrew and remove the bowl underneath. then, remove the float-valve (little brass valve where the fuel line comes into the bowl.) Don't lose the spacers as you remove it.

They have a habit, especially the versions without screens on them, of buggering up with even the finest grit and sticking.

It will amase you what can get past fuel filters, and sticking or clogged valves are a weakness. I've had to clear them on the side of the road before. The photo shows you a rather extreme case I encountered recently...

If that isn't part of it, check your overflow tube for flooding, then on to the choking system.


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Sarge101st Avatar
Sarge101st Silver Member Brian S
Carlisle, PA, USA   USA
1977 Triumph Spitfire 1500 "Biggles"
1979 MG Midget 1500 "Grrr"
1980 MG MGB "Piddles"
By the way, one wonders whether your charging system is working properly. Have you checked the output at idle? Someone mentioned it earlier on and the squeaking at low revs causes me to wonder.

Anyway, please realise I can only make common sense guesses and suggestions, since I can't put my hands, nose, and ears in the engine bay. I can easily be 'way off, so these should be taken only as suggestions as possible places to look.

Mavrick Avatar
Mavrick Jan Jacobs
Brugge, West vlaanderen, Belgium   BEL
Hi, gents a little update, dismantled the stromberg carburettor, cleaned it and put it back , started engine same problem!

jimbo20 Jim S
Welwyn Garden City, Herts, UK   GBR
Have you put some oil in the stromberg dash-pot?

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Mavrick Avatar
Mavrick Jan Jacobs
Brugge, West vlaanderen, Belgium   BEL
Yes I did

Mavrick Avatar
Mavrick Jan Jacobs
Brugge, West vlaanderen, Belgium   BEL
hi, a update, measured the ignition coil, the spark plug wires, all oke. set the timing, cleaned the spark plugs, still the same problem, i made a video, i hope somebody can point me in the right direction.


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CountBasey Avatar
CountBasey Thomas Basey
Brunswick, OH, USA   USA
1976 MG Midget 1500 "Opus"
Strange sucking sound when you try to give it throttle - mine doesn’t make that noise. Is the air cleaner new (not the filter - the housing)? I’ve never seen one like that before, at least not from that angle in the video. Are you sure it’s not air starvation? Have you tried with the filter off - or at least the housing opened up and no filter?

If not the air cleaner, my second guess is a vacuum leak, but the question is where. I’d have to look at my setup vs yours in the video and see if there is anything obvious. Did you recently plug any of the intake openings, or remove any lines?

All just guesses.



Thomas (Count) Basey
Member of Emerald Necklace MG Register - www.mgcleveland.com
________________________________________________________

“With each replacement of parts, my British car slowly becomes Chinese.”

CountBasey Avatar
CountBasey Thomas Basey
Brunswick, OH, USA   USA
1976 MG Midget 1500 "Opus"
Looking at the video again, looks like the EGR valve on the intake manifold is removed, but doesn’t look plugged. There is also a vacuum line attachment right behind it on the manifold with no line attached. Were they both this way before you did your clutch job? Have you tried covering the EGR valve hole up? Again, just being Captain Obvious here.



Thomas (Count) Basey
Member of Emerald Necklace MG Register - www.mgcleveland.com
________________________________________________________

“With each replacement of parts, my British car slowly becomes Chinese.”

Mavrick Avatar
Mavrick Jan Jacobs
Brugge, West vlaanderen, Belgium   BEL
hi, well the engine has been out because i had to replace the clutch, and when i connected everything the made a tour with the car, no problems at that time, the day after the car did this strange thing.

Mavrick Avatar
Mavrick Jan Jacobs
Brugge, West vlaanderen, Belgium   BEL
its plugged, it was like that when i purchased the car 5 years ago

CountBasey Avatar
CountBasey Thomas Basey
Brunswick, OH, USA   USA
1976 MG Midget 1500 "Opus"
In reply to # 3734507 by Sarge101st If that isn't part of it, check your overflow tube for flooding, then on to the choking system.

Just grasping at straws, but the post above got me thinking. You said it runs poorly when cold, but after it warms up it runs better... would you say it's "normal" after it's warmed up? It appears you have a manual choke. If it was stuck open, I would think the car would start fine when cold, but then have some high RPMs once it warmed up. Since you have the opposite problem, is the choke working/engaging correctly on a cold start? (I know you said you just cleaned it up, so this is probably a long shot).

When I start mine cold, I always go 3/4 to full choke, and once the engine fires I slowly back the choke off. Do you do the same with your 76 on a cold start? If so, have you ever tried starting it cold without pulling out the choke? I'm curious if yours would fire without the choke and perhaps run the same as in your video. Maybe it's not choking during startup?

Since my setup is identical, I'm almost as eager as you to know the issue in case this ever happens to me. You have me stumped!



Thomas (Count) Basey
Member of Emerald Necklace MG Register - www.mgcleveland.com
________________________________________________________

“With each replacement of parts, my British car slowly becomes Chinese.”

Mavrick Avatar
Mavrick Jan Jacobs
Brugge, West vlaanderen, Belgium   BEL
Hi, well after the engine is warm is runs better but still not good or perfect.
Indeed it’s a manual choke and if I do not use the choke to start she dos not start.
When I pull the choke full open is seems like she in drowning. So from the moment the engine starts I push the choke back then the stuttering starts at a very low rpm. The choke works fine by the way.

Do you also have a stromberg Carburetor? If yes can you take some pictures of it, to see your connections and what is damped and not.

Greets
Jan

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