Hi all
New to the Morris Minor and this site.
Have a problem with my 1963, 1000. Car drives great and is very responsive, problem is when it is just ticking over at low revs it runs really lumpy and is only happy when I pull the choke out and the revs go up. What could this problem be? I have replaced points and condenser.
As you can tell by my description, don’t know much about the oily bit on cars, suppose now I have a moggie I should start to learn
Any help would be great, Paul
Car runs really lumpy at low revs
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rayofleamington
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if you raise the tickover is it better?
Lumpy running at low revs can be may things (poorly set up carb etc..) but may be a sign of valve wear. Leaking valves have a bigger effect at low speed as there is more time for the gases to leak, and even with a badly burnt valve or seat an engine will seem fine at high revs.
Therefore if the basic checks don't reveal anything you should look to get a compression test done
Lumpy running at low revs can be may things (poorly set up carb etc..) but may be a sign of valve wear. Leaking valves have a bigger effect at low speed as there is more time for the gases to leak, and even with a badly burnt valve or seat an engine will seem fine at high revs.
Therefore if the basic checks don't reveal anything you should look to get a compression test done
Ray. MMOC#47368. Forum moderator.
Jan 06: The Minor SII Africa adventure: http://www.minor-detour.com
Oct 06: back from Dresden with my Trabant 601 Kombi
Jan 07: back from a month thru North Africa (via Timbuktu) in a S3 Landy
June 07 - back from Zwickau Trabi Treffen
Aug 07 & Aug 08 - back from the Lands End to Orkney in 71 pickup
Sept 2010 - finally gave up breaking down in a SII Landy...
where to break down next?
2013... managed to seize my 1275 just by driving it round the block
Jan 06: The Minor SII Africa adventure: http://www.minor-detour.com
Oct 06: back from Dresden with my Trabant 601 Kombi
Jan 07: back from a month thru North Africa (via Timbuktu) in a S3 Landy
June 07 - back from Zwickau Trabi Treffen
Aug 07 & Aug 08 - back from the Lands End to Orkney in 71 pickup
Sept 2010 - finally gave up breaking down in a SII Landy...
where to break down next?
2013... managed to seize my 1275 just by driving it round the block
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Cam
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- Location: Stoke-on-Trent, Staffordshire, UK
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It COULD be that it's running rich a bit (does it sound like it's 'hunting'?). When you pull the choke out a bit although you are making it EVEN MORE rich, you are also raising the tickover speed via the fast idle cam which will stop it stalling.
What colour is the inside of your exhaust and your spark plugs?
What colour is the inside of your exhaust and your spark plugs?
Websites: 
Hi, thanks for the replies.
The head had the valves done and a new head gasket fitted at a garage before I bought it so don’t think that could be the problem.
Spark plugs seem fine so is the exhaust. The only reason I pull the choke out a bit is to keep the revs up so it runs smoothly, if I don’t it runs erratically and not smooth.
Hope that helps a bit?
Hunting?
Thanks again, Paul
The head had the valves done and a new head gasket fitted at a garage before I bought it so don’t think that could be the problem.
Spark plugs seem fine so is the exhaust. The only reason I pull the choke out a bit is to keep the revs up so it runs smoothly, if I don’t it runs erratically and not smooth.
Hope that helps a bit?
Hunting?
Thanks again, Paul
Paul,
If the mixture is too rich at tick over, the revs increase (more fuel = more power), but then dies away because there isn't more fuel/air mixture, andthe cycle repeats. Technically "hunting"...
The easiest checks are:
1) Air filter - when was it last changed? - is it filthy dirty? (choked air-filter = not enough air -> rich mixture)
2) Air filter - pipe from rocker to air filter - is it bunged up with oli/water mayonaise? Mine was nearly blocked after the winter - lots of shortish runs. Appears fairly normal with moggies.
3) unscrew the black plastic knob in the SU Carburetter - there should be oil inside (my book states SAE 20, others use 20W/50). That damps the piston in the carburetter to avoid rapid changes.
4) Check all plug leads and connections (sometimes the connectors on the plugs unscrew)
5) Check the idle mixture of the carburetter - typically with the Gunson device - this is a large nut under the carburetter, but doesn't normally change its setting without "help"
6) Check the points, etc., and the idle speed.
Let us know how it goes...
Colin
If the mixture is too rich at tick over, the revs increase (more fuel = more power), but then dies away because there isn't more fuel/air mixture, andthe cycle repeats. Technically "hunting"...
The easiest checks are:
1) Air filter - when was it last changed? - is it filthy dirty? (choked air-filter = not enough air -> rich mixture)
2) Air filter - pipe from rocker to air filter - is it bunged up with oli/water mayonaise? Mine was nearly blocked after the winter - lots of shortish runs. Appears fairly normal with moggies.
3) unscrew the black plastic knob in the SU Carburetter - there should be oil inside (my book states SAE 20, others use 20W/50). That damps the piston in the carburetter to avoid rapid changes.
4) Check all plug leads and connections (sometimes the connectors on the plugs unscrew)
5) Check the idle mixture of the carburetter - typically with the Gunson device - this is a large nut under the carburetter, but doesn't normally change its setting without "help"
6) Check the points, etc., and the idle speed.
Let us know how it goes...
Colin