Engine cutting out after not driven for a year.

[James k]

Hi,

I haven't driven my Morris for a year and today, took it out for a drive. The engine starts and runs and idles smoothly, but when driven, the engine periodically cuts out. The dashpot isn't stuck, the choke isn't stuck on, the fuel pump is working correctly and I've cleaned up the coil contacts. What should I be checking next? It's not sputtering to a halt, it's just cutting clean out.

Thanks,
James

[geoberni]

Condenser and/or HT lead breaking down...
Corroded wiring connections, including earths....

In this weather it could be a combination of things, made worse by the damp.

[les]

Someone here is going to say ——-test this and test that—— but it you’ve got a few spares then no harm in trying one thing at a time, include changing the rotor arm.

[James k]

Thanks for the responses. Thinking about it, doesn't the fact that it just cuts out cold suggest that it's a problem on the LT side? If it were HT, wouldn't it be more likely to start running rough? As it is, it's just like you've switched the ignition off.

It's electronic ignition so no condenser.

[Myrtles Man]

It'll be the coil.

[moggiethouable]

Check the small cable tucked under the distributor cap that leads from coil to the points, it makes and breaks with the shake of the engine when faulty.
Part number 7 shown.
Actual part number DST 107 its only a few quid.

[myoldjalopy]

Someone here is going to say ——-test this and test that—— but it you’ve got a few spares then no harm in trying one thing at a time, include changing the rotor arm.

Yes, it could be the rotor - I had one that periodically failed and the car would stop suddenly. Then it would be OK again for a while. Eventually a new rotor arm fixed it for good. Or the electronic ignition gizmo may have gone kaput.....

[James k]

Thanks, I'll check those bits tomorrow. The fact that it's happened after being in storage makes me suspect corrosion. The leads are pretty new (just before it went in storage), could they have degraded in that time?

Like I said I cleaned up the connections to the coil but I haven't checked at the fusebox end. I'll check under the distributor cap too. It could be that the contact on the rotor arm is corroded, couldn't it?

[StillGotMy1stCar]

Rotor arm failure is normally a short or arc from the contact through the plastic to distributor shaft.
I have had this as an intermittent fault.

Regards John

[myoldjalopy]

Thanks, I'll check those bits tomorrow. The fact that it's happened after being in storage makes me suspect corrosion. The leads are pretty new (just before it went in storage), could they have degraded in that time?

Like I said I cleaned up the connections to the coil but I haven't checked at the fusebox end. I'll check under the distributor cap too. It could be that the contact on the rotor arm is corroded, couldn't it?

Unlikely that new leads would degrade in just a year. If the issue is corrosion on the rotor arm contact, it should be very obvious on inspection. I don't think it likely though in your case. If it is the rotor arm, it is more likely that the rivet is intermittently shorting out. See the Distributor Doctor's explanation of the problem here: https://www.distributordoctor.com/rotor_arms.html I have certainly experienced this problem in the past and one of the good doctor's red rotors has cured the issue for many years now.

[exlkrs]

Basically, a car is just a big working (or not) model of the Fire prevention triangle. Remember the mandatory fire lecture you dozed off in? So, to recap, Fuel, Oxygen, Ignition. Remove one, and it don't happen. So, after storage there's a good chance on of the three elements has gone awol. So, if you rule out manky fuel and Roland rat demised in you air filter housing, and check electrical stuff, you should be fine.

[geoberni]

It'll be the coil.

That was the problem with my car when I first brought him.
I trailer-ed him home not wishing to risk 75 Miles with an unknown vehicle.
Local driving around the village was fine.
First long trip out, got around 6 miles from home and cut out on the A1.
RAC blamed the 'Electronic Ign' for no spark.
Once recovered home, all was working perfectly....
So I brought a new Electroinc Ign unit as I didn't know how old the fitted one was.
I couldn't fault it and trips of about 10 miles or so revealed no problems.
Next long trip out, 29 miles, cuts out again.
RAC call out, again blamed 'Electronic Ign'....
Still dead when we got recovered home.
Quick check with the multimeter revealed Open Circuit Coil.
Some time later I opened the Coil up and posted the results on this topic:
viewtopic.php?p=636467#p636467

So don't discount it being the Coil...

[Myrtles Man]

I'm not discounting anything my friend, I was merely invoking the long-running light-hearted badinage that arose on this forum following the late bmcecosse's (I think that's right) contention to that effect.

[svenedin]

I'm not discounting anything my friend, I was merely invoking the long-running light-hearted badinage that arose on this forum following the late bmcecosse's (I think that's right) contention to that effect.

Yes it was Roy (BMCecosse) who was adamant "it's never the coil" (unless it is)......

I think it is fair to say that the old coils very rarely failed and there are many cars still happily driving around using ancient coils. The same is not true of the modern coils. One (expensive) brand of coil with an excellent reputation are those made by Pertronix. Distributor Doctor highly recommends these coils but note they have a larger diameter than the original coil and need a new bracket.

Stephen

[geoberni]

I'm not discounting anything my friend, I was merely invoking the long-running light-hearted badinage that arose on this forum following the late bmcecosse's (I think that's right) contention to that effect.

Yes, I got the reference; he was still around when I joined this Forum.

Yes it was Roy (BMCecosse) who was adamant "it's never the coil" (unless it is)......

I think it is fair to say that the old coils very rarely failed and there are many cars still happily driving around using ancient coils. The same is not true of the modern coils. One (expensive) brand of coil with an excellent reputation are those made by Pertronix. Distributor Doctor highly recommends these coils but note they have a larger diameter than the original coil and need a new bracket.

Stephen

I agree, the quality of modern Coils is poorer. I don't think they are up to the job of being mounted on top of the Dynamo/Alternator, so I moved mine back to the original bulkhead position.
I think the original Coils were over engineered, using heavier materials, so could better take the abuse of the vibration.
Modern manufacturing requires the minimum amount of material to do the job thus keeping cost down, and personally, I don't know of another conventional single Ign Coil engine that has it bolted to the principle source of the vibration...

[myoldjalopy]

Roy was always clear that his motto did not apply to modern coils - nor include the coil connections.

[James k]

Hi again,

Sorry for the delay, I've just been a bit overwhelmed with work and other stuff. I attempted to troubleshoot the car again but with no luck. I thought I'd found the problem at first as the positive connection to the coil was corroded and the wire snapped when I handled it. I fixed that, though, but it had no effect. I kept at voltmeter on the coil and the supply voltage is not cutting out when the engine does, so it's nothing on that side. I did revisit the carb again, in case the jet was blocked. I disconnected it from the float bowl and blew through it to make sure that it was clear but, again, no luck.

I had the car recovered in the end and put back in the garage. Realistically, I probably won't have a chance to look at it again until the summer, which is a shame.

Thanks again for all the suggestions.

James

[geoberni]

I kept at voltmeter on the coil and the supply voltage is not cutting out when the engine does, so it's nothing on that side.

But are you getting anything on the Low Tension out of the Coil?
Coil should have continuity of about 3.9 Ohms between the LT connections.

[myoldjalopy]

It seems we will have to wait until next summer to find out!