Help!

[Mad Grandma]

My Minor will run for about 10 miles or so then conk out. After about 20/25 minutes it starts and I can go another 10-15 miles when it does it again. I have had a new battery, a new coil and a new condenser fitted but it is still happening. I am afraid to go out in it as it is so unreliable. Any answers please. Thanks

[oliver90owner]

Is it the ignition system that is the cause? If not, it is likely the fuel supply.

[philthehill]

Sounds like fuel vaporisation in the feed pipe which is a well known Minor problem especially in this hot weather.
You can get a kit to help shield the fuel pipe from engine heat.
https://www.morrisminorspares.com/fuel- ... ly-p830677

[geoberni]

My Minor will run for about 10 miles or so then conk out. After about 20/25 minutes it starts and I can go another 10-15 miles when it does it again. I have had a new battery, a new coil and a new condenser fitted but it is still happening. I am afraid to go out in it as it is so unreliable. Any answers please. Thanks

We need to clarify what you mean by 'Conk Out'; does it splutter and stop or suddenly act as though you've switched it off?
When it does it, pull a Plug lead off, hold it close to the plug top and then turn it over, if you have a later model without a push button under the bonnet, this will of course require a 2nd person.

Then we know if it's an electrical problem, or as Phil says, a fuel problem.
How long has it been happening, and was any investigation carried out before replacing the Battery, Coil and Condenser?

[jaekl]

Listen to the fuel pump. It will tell you just about everything about the health of the fuel system. What colour is the distributor rotor?

[myoldjalopy]

" How long has it been happening, and was any investigation carried out before replacing the Battery, Coil and Condenser?"
This.

[simmitc]

How "mechanically minded" are you? There are plenty of things that we can suggest. but the level of detail can be tailored to suit you.

My first suggestions: Make sure that you will be somewhere safe to pull over, then drive until the problem occurs. Switch off ignition. Remove and replace the fuel cap. Switch on the ignition. Does the fuel pump click? If no, then open the bonnet and tap the fuel pump. Does it click now? Does the engine start?

Those are simple things. If they do not produce a result, then we can get a bit more complicated.

[Dogsdad]

Try a new rotor arm.
A car of mine (1938 Standard 9) used to do this.
The rotor arm was shorting through as it heated up.
Once it cooled the car would start and run again for ten minutes or so then stop again.

.

[myoldjalopy]

It could, indeed, be the rotor arm and 'jaekl's question about its colour is pertinent. If it is red, it is probably OK but there have been problems reported on here in the past with the black ones. I, myself, have had black rotor arms failing intermittently in the past but no problems for several years after fitting a red one from the good 'Distributor Doctor'.

[Mad Grandma]

Thanks for the info - I've ordered a red one!

[olonas]

"I've ordered a red one!"
Which doesn't guarantee it will be good or durable.

Have a read through this too. https://www.distributordoctor.com/red-rotor-arms.html

If it is one of those cheap copies it could at least determine if that is the issue though.

[myoldjalopy]

Well hopefully our mad friend will have ordered from the Dizzy Doc.

[oliver90owner]

Swapping parts willy nilly is often a total waste of time and money. If it is a fuelling problem (not an ignition issue), that will be quite obvious to all but those thst always blame any item they have experienced (or heard of).

If fuel, it could be as simple as a now-unvented fuel tank. It could be other, less likely faults.

[Peted7202]

Swapping parts willy nilly is often a total waste of time and money. If it is a fuelling problem (not an ignition issue), that will be quite obvious to all but those thst always blame any item they have experienced (or heard of).

If fuel, it could be as simple as a now-unvented fuel tank. It could be other, less likely faults.

You are right Oliver.

Basic problem solving process will help before firing the parts cannon

Asking what is wrong with what and separating out if more than one problem?
When did the problem start?
What's changed immediately before the problem started?
What is the extent of the problem, the symptoms/effects?
Identify possible causes and test against the symptoms/effects. How would these causes create the effects?
What non invasive testing can be done?

[myoldjalopy]

I agree, and 'geobernie' earlier posted the query " How long has it been happening, and was any investigation carried out before replacing the Battery, Coil and Condenser?", which I seconded, but to which there was no reply. Without answers to questions like this, trying to obtain more information, it is often difficult to get beyond 'well, it could be this, or it could be that'..............the more detailed information we get, the more likely it is that we can provide more structured advice.

[olonas]

"Swapping parts willy nilly is often a total waste of time and money."
Agreed. This is what often happens with a modern car. Computer says something is faulty. That part is replaced when it is something else causing that part to show as faulty. Then it's just chuck parts at it until the problem hopefully goes away.
However, for the cost of a relatively cheap rotor arm it's probably worth firing the cannon to eliminate that component. Even one of those so-called Lucas items.

[les]

Well you don’t do it willy nilly, you do it because a you may have the part to hand and because you have an idea that it might be the answer, if it’s not then you have another think. Nothing wrong in analysing, however all these ideas that you can’t do anything until you’ve done every test in the book and convinced yourself of the problem is ok in theory but you still might be wrong, then heaven forbid, you may have changed a part that wasn’t the problem anyway, just like a willy nilly person !!

[myoldjalopy]

Well, in any case, it will be interesting to find if this new rotor arm fixes the problem or no!

[oliver90owner]

Well, in any case, it will be interesting to find if this new rotor arm fixes the problem or no!

It most certainly will not - if it was never an ignition problem! Checking for a spark is so easy and should be the first check at the time of failure, unless there is another obvious issue. A good spark, and no start, at that time would almost certainly rule out an ignition fault.

[myoldjalopy]

Well, that much is blindingly obvious, but as 'Mad Grandma' has now already ordered a rotor arm, it will still be interesting to see if the problem is cured or not.........