Morris Minor Owners Club

Following on from Dotty's car not starting: my 1275cc, electronic ignition, negative earth car, starts and runs for a short while then suddenly dies and then picks up again. Its definitely an electrical problem as, when it dies (sometimes in an embarrassing traffic situation) the electronic rev counter I have drops to zero and the ignition warning light comes on. It will burst back into life most times but occasionally I have to stop and do a restart on the key. Is this likely to be an intermittent coil problem?

If the engine dies completely then the rev counter would show zero and the ignition warning light would come on - the engine has dies, so no revs or generation. Do other ignition switched items such as indicators, heater fan and wipers still work? If no, then the problem is likely to be a general supply issue or the ignition switch.

If the engine is still turning then I wonder about a loose connection in the ignition feed. I would start by double checking all connections from the ignition switch to the coil. Make sure that all spade terminals are a good fit and are securely crimped to the wire.

Fuel starvation can also cause the engine to die and then pick up, but start with the connections.

Thanks for advice. Will carry out checks and monitor situation. The problem mainly occurs after a short, 3-4 weeks, lack of activity. After a run out, Tilly behaves herself. Perhaps it's damp?

The points in the fuel pump are prone to misbehaving after sitting for a while in damp conditions. Usually the car won’t start in those circumstances but no harm in giving the points a clean along with the other checks suggested. Modern fuel also “goes off” rather quickly and can cause the needle valve in the float chamber to stick. If you do find it is fuel pump points related you can get a kit to convert the fuel pump to electronic operation which eliminates that problem. Frequently used cars don’t seem to suffer so much as the points are in theory self-cleaning to a degree. Likewise there is a Viton tipped needle and a “stay-up” float available which is resistant to ethanol containing fuels. This may not be relevant if it is an electrical problem. Sometimes a crimped connector feels “floppy”. Some of the wires have fractured and it is no longer making a reliable connection.

Indicators still work during engine cut out time. I thought that if it was fuel related, the engine might have stuttered rather than cut out abruptly.
Again thanks for all the pointers

I had a fuel problem that was intermittent and caused some embarrassing and awkward breakdowns. The only way I managed to diagnose it definitively was to take the top off the float bowl when the engine had just cut out. Sure enough the bowl was dry. If you want to try that have a new gasket to hand in case it leaks afterwards.

A dodgy connection inside the coil is not impossible; it happened to me. In France, and in the rain!
But you need to have the fault solidly in place to track this down.
With the coil disconnected use a DVM to measure the ohms between the two spade contacts. It should be about 3 ohms. If it reads open circuit, it's broken. Similarly between either spade and the HT connection it should be 10k to 20k; not open circuit.
No DVM? Just replace the coil with your spare to see it clears the problem. You DO carry a spare??

Again thanks for all the helpful info posted. In the interim I have just changed the fuel pump and coil but the problem still persists! For instance, on initial start up the engine runs fine. On allowing the car to tick over at rest, after about 30 seconds it just cuts out. Start again, same symptoms. I now intend to run the car, again at rest, with the fuel cap off to see if there is a vacuum in the fuel line. Next will be the float bowl investigation. It's very frustrating and for the moment I've had enough!!

Crap in the fuel tank? Although your new pump and its filter should have eliminated any crud getting through, it is possible that there is debris in the float chamber, occasionally causing the needle to stick. A look in the float chamber may give you a clue......

Alex
Have you ruled out the low tension lead on the Lucas Distributor (? don't know what you have on the car).
The electrical lead covered in cotton fabric cannot be described as being robust , more like delicate. If it is original or a bit" long in the tooth " then the wire may be fraying unseen. The intermittent nature suggests some loose connection scenario which , if left unresolved , will result in a permanent "no go ". Can I suggest connecting both ends to a Multi meter, set to Ohms, on the disconnected earth wire, trying the wiggle manoeuvrer to see if you get a stable reading throughout the shakedown. If only to eliminate it from the equation.
If the reading fluctuates then , you have a problem Houston. Panic not , Lucas earth Distributor leads don't cost a fortune. Here's an ESM's link
but there are other suppliers available :-
https://www.morrisminorspares.com/ignit ... d4-p831044
Good luck on hunting down the problem , Bob

myoldjalopy wrote: ↑Sun Apr 23, 2023 2:02 pm Crap in the fuel tank?

Well, if he did, it's not surprising that it keeps cutting out!

Ha ha! Beauty! That did make me laugh

Ours had a gauze filter on the pick up inside the tank which blocked, blowing backwards through the fuel line would clear it for a while. You can't get the filter off though so it's either a new tank or fabricate an alternative fuel pick up which I did through the level sensor.

I had an issue with an inline fuel filter in thr flexi fuel line to the carb. Removing it fixed the issue

Any luck finding the cause of this problem? I believe it helps the forum to be a much more useful resource if the problems actually gets diagnosed and fixed.

Stephen

I agree Stephen although, to be fair to the OP, he does have a number of possible scenarios to follow up,as suggested by various members of this forum.

I am taking all the points made on board. It's slow progress at the moment due to it being a bit too cold to work outside -it was -0.2 overnight here in the Highlands. I have however ordered and awaiting a float bowl kit from ESM. I will let you all know the outcome one way or another.

Thank you Alex. I didn’t realise you were so far North. Mind you we had a frost down South too! To remove the float needle valve seat you need a thin walled special socket. A normal 11/32" socket will get stuck. Perhaps you’re not doing that though

With my limited knowledge (enhanced of course by members on here!), and my lack of ability l am now totally flummoxed. "Tilly" will be going to my local classic car magician - over 50 years experience - next week for a proper diagnosis and smacked bottom!
Once she has recovered, I will let you know what the problem was.

I I wonder if this little dicky is retained with an electronic ignition, as I have kept my points I wouldn't know.
But what I have experienced is the cable making and breaking, so I replaced it and my intermittent cut out went away.