Morris Minor Owners Club

Hi, I am still having problems with my engine!
It is running really roughly on tickover, I had adjusted the mixture as it was too rich (black sooty plugs & exhaust!) and tried to adjust idling speed with no success.
Took it to local garage (who have a Minor "expert" there and are very good) and they replaced points and condenser & retimed engine. Got it back and it kept cutting out unless I had choke out all the time, so took it back and they readjusted mixture & put some oil in the carb. They also said my distributor was loose.
It's still not right, just sounds really rough & uneven when idling, I will take it back tomorrow, wondered if any of you have any ideas. Once it has warmed up properly it's a bit better, but not much!

Well - I seriously doubt their 'expertness' if they adjusted the timing - and then said later the dizzy was loose ? And they gave it back to you still not running correctly ??
First move here is a check/reset of the valve gaps - and then a compression test to judge the condition of the engine. It may have a burned valve or some other malady.

Hmm, hoped I had found a good garage! Trouble is I suppose being female and not very clued up about cars apart from the basics it's hard to tell.
Will investigate valve gaps as you suggest. Thanks for your advice!

And then do compression test - and ask them for a note of the results in each cylinder - not just " it's ok" . They should do a round of tests as the engine stands - then again after adding a squirt or two of oil to each bore - but in practice that tells very little - -so don't insist on it!

Put your location on your profile and if anyone is local they may be able to take a look

I had similar-sounding problems this week, so I changed the plug leads after investigating everything else - instant remedy! These things deteriorate in strange ways.....perhaps an expert could give more info on why this is?

Is it still possible to buy Colourtune? I have it - just a spark plug with a glass 'window' in it, and an observation tube with a hinged mirror for viewing the action from any angle.

Great fun! You can see the explosion in the cylinder! All you have to do is richen the mixture(by screwing the jet nut downwards) so the burn is yellow at tickover, and then gradually weaken the mixture (by screwing the jet nut upwards) until the yellow has just disappeared and you have a pretty bunsen blue flame. Then you can gradually (slowly) increase the revs, and you should have a constant blue burn throughout the range.
Remember to check that the jet is centred after the adjustment. There is a procedure, but I don't know what it is as I've never had to follow it. Tickover may need to be adjusted after setting the mix. Probably best done with a new air filter.
It's a great method of setting the mix - you can't argue with what you can see!

Plug leads do get wet and oily - and the carbon 'string' inside starts to break up - so yes they do detriorate and new leads can't do any harm. May very well be the problem here - as could a number of other distributer related things! It's perfectly possible to set the idle mixture without colortune (using the lift pin) - and I do believe it's not supposed to be used at anything above idle - in case it explodes!

Something I forgot to mention, my husband checked the plugs and has told me that only 3 were black & sooty, one was completely clean, could this be part of the problem?
Will take car back to garage & ask for compression test. Does loose distributor mean getting a new one or can it be adjusted?
Sorry for so many questions, am gradually learning things thanks to this forum!

Re Colourtune: I have the instruction booklet and followed the procedure to the book, regarding the increase in revs. Perhaps things have happened in the past as you described.
I suppose if you put one in a huge, turbo-charged engine and took it up to full revs, something detrimental might happen. I just took my Morris up to about 2,500rpm for a short time.....enough to enjoy the fascination.
According to the information on the box, it is AA approved and recommended by BLMC (showing my age!), Rover, Ford, Chrysler UK, Saab GB, Tecalemit-Jackson, Toyota and Mazda GB.
Here is an extract from the Gunson (manufacturer) site:

This product may be used at a wide range of engine speeds but should not be used in
an engine under load as overheating and product failure could occur. Take additional
care when using the product on an air cooled engine which has no fan assisted
cooling. On these engines limit the total test duration to 5 minutes and avoid
extended running at high rpm.
• The viewerscope supplied with this product is made from a glass reinforced heat
resistant material but will be damaged by excessive heat before the Colortune plug.
If this is damaged it serves as a clear warning of overheating. Obtain a replacement
and take more care to avoid overheating. Discontinue use if the product plating is
discoloured by heat or the glass / ceramic shows signs of damage.

Also, it retails at around thirty pounds! I was lucky - I got mine for a quid from a re-cycling centre!

Re distributor: I wouldn't imagine you'll need a new distributor. Even if it were loose for a long time, it wouldn't really move about in a way that would induce catastrophic wear.
There is a clamp between the distributor and the engine block. The clamp bolt has a square head and is locked in place, so it just needs a 7/16th inch spanner to nip up the nut - this only needs just enough force to secure the distributor in place. Overtightening achieves nothing. If you can't turn the distributor by hand, then it's tight enough. Maybe a good idea to check before making the final adjustments, to get the feel of it, as you obviously don't want to move it once it's been set.

Another point re Geraldine's problem - I've forgotten the name of it, but there's a special kind of wire in the distributor, in rather loose-fitting insulation, connecting the points to 12volts. I've only had a problem with this once in all my motoring years - but it cost me several hours of futile investigation in other areas.

Also, I've just the once had a failing coil. How you check the condition of this I have no idea. Best plan of attack would be a substitution, to see if things improve.

Re the one clean plug and three sooty ones......????? A compression test could shed more light on the reason for this. Hard to imagine three cylinders being down, though.

One clean plug and three sooty ones suggests either that plug isn't sparking (no combustion, no soot) or just possibly the inlet valve isn't opening.......(though that would be shown up in the compression test.

Loose distributer should just mean that the clamp bolt needs doing up - it's possible that the clamp plate may be damaged - it's possible that the distributer body has worn if it's been loose for ages but neither is particularly likely.

Edit: Some of which Mick has already told you, obviously writing away at the same time as me!

I think you need a friendly local club member to have a look at your car Geraldine. I can't remember your location but I seem to remember not near me (Kent) otherwise you would be very welcome to drop round.

Always buy copper core HT leads, they are more reliable than carbon core leads. You should be able to by a length of HT lead and cut it to size, leaving some spare which you can keep in the car for emergencies.
Any competent garage mechanic should be able to diagnose and fix a misfire on a simple engine like a Minor. If he comes up with strange excuses then he is trying to fleece you so go elsewhere.
Loose distributor unlikely but other things to check:- take the cap off and try turning the rotor arm, it should move a little then spring back. If not then the dizzy springs have come adrift - fairly easy repair.
Try moving the rotor arm from side to side. If there is any movement on the distributor shaft then the bushes are worn and it needs replacing.
Check the carbon bush in the top of the cap. This should be sticking out and should press in and spring out
If you can run the engine at night in a dark garage for a couple of minutes you may be able to see sparks if there are any short circuits such as damaged HT leads touching the engine or bodywork

Yes - it rather depends whether they meant 'loose' internally - or 'loose' where it bolts into the block!
Copper HT leads are fine - but illegal unless you also fit interference suppressing plug caps - or in line suppressors in each HT lead. Carbon string is fine - just don't expect it to last 'for ever'!
The single 'clean' spark plug will usually indicate a water leak into that combustion chamber - the plug, and indeed the whole chamber is likely to be spotlessly clean ! The leak could be from head gasket or from cracked cylinder head.

The

a special kind of wire in the distributor

is called a rats tail, well that's what I've heard it called and it seems appropriate .

'Pig tail' according to Minispares. http://www.minispares.com/Product.aspx? ... %20WIRE%20...
I've always known it as the 'low tension lead'

I am having compression test done tomorrow, will post with results when done!

I agree with Mike - if your local garage can't sort out a mis-firing A series engine in about 30 minutes or at least be able to identify the fault then they're not up to much. Misfiring is usually spark related, either dizzy, plugs or leads. Looking forward to hearing the end of the story though!

Yes it's quite disappointing as they are just around the corner, and are very pleasant to deal with - but it's results that count and they haven't managed to sort out the problem!
There is a garage in Ipswich that deal with classic cars, but they are right over the other side of town, will have to investigate them.

Pretty much any mechanic worth their salt should be able to diagnose & cure missing on an A-series engine ... there isnt all that much to them!

'Pig tail'? Must be due to being so pink and curly .

alainmoran is spot on, a mechanic will have no problem sorting out an A series engine.

Unfortunately modern cars tend to encourage "fitters" who will expect to find the faulty module, replace it, job done.

You need to find someone who uses knowledge and not a laptop to sort it out or learn how to do it yourself. It isn't very hard and is very rewarding.

My 2ps worth is the head gasket has gone and needs replacing. An easy job compared to an overhead cam engine.

Phone around until you get a decent quote.