Morris Minor Owners Club

Morning all!

Took the Mog out for a long-ish drive on Sunday and found it was missing quite badly. This happened a while ago and turned out to be a loose screw in the distributor and the points had sprung open. Not the case this time, though, and I had a feeler gauge with me so checked the gap. It did it on-and-off all day and at one point on the way back I thought I might have to call the RAC. Every time it did it, I opened the bonnet and removed the distributor cap and checked everything. All seemed OK and when I started going again it was fine for a few miles before starting again and getting prgressively worse until I needed to stop again. I probably stopped 4 or 5 times over a 70 mile journey.

The only things I thought were:

- Rotor arm was not replaced at the last service (and I don't know when it was replaced before that) due to my "service kit" containing a dizzy cap instead. Haven't got round to getting a new one yet and the current one is pretty tatty
- Slight leak from the top of the radiator I hadn't noticed before (I assume a bottle of "stop leak" from Halfrawds will do the trick?)
- Slight leak from a small hose which appears to be something to do with the heater. Again, I hadn't noticed it before

If anyone's got any ideas I'd like to hear them. I wonder if it's overheating slightly as it seems to go OK after stopping a few minutes but that's only a guess and from the sound of it it's an electrical problem.

Please help!

Neil

You can clean the contact edge of the rotor arm to see if this helps just rub it on the side wall of one of your tyres this will polish it up, did you chech the cap contacts in case the rotor arm has caused them to deteriorate also ahve a look at the points are the faces becoming discoulored (you can do this without removal) if so I would suspect the condensor, also check that the cap has not developed a crack, if its dark you can often see the spark tracking across the cap.

hard to explain, but what kind of missfire?

these can sometimes be a pig to find, as they are not always the electrics. I've even heard of leaky hoses causing a jet of water on to the electrics, but only when hot.
Other odd things things could be fuel starvation, but the list is very long.

It could be your coil / coil connections, we have had this before and it seemed to be heat related. When it had cooled down a bit it was OK again for a while.

Previous posts have been due to coil and fuel pump problems - but it could be a loose connector as well. Very likely to be electrical. I seem to remember someone had similar problems caused by a loose screw (which fastens the condensor to the distributor).

Previous posts have been due to coil and fuel pump problems - but it could be a loose connector as well. Very likely to be electrical. I seem to remember someone had similar problems caused by a loose screw (which fastens the condensor to the distributor).

I think Chris has spent too much time thinking about this problem or he's experienced it 3 times !!!

These misfire problems can take forever to trace but are nearly always something simple.
Of course, it's only the intermittent ones that are difficult. When it stops altogether, it's easy to find the cause (usually). Unfortunately it's always at the wrong time.

When I first saw the topic my immediate thought was how are they getting around?
Something that is often neglected on the distributor cap is the small centre carbon brush which transfers the HT current from the coil to the rotor arm. If this is worn, sticking or the spring is weak it can cause a misfire or nothing at all.

For the high tension side - open the bonnet in the dark with the engine running. I root caused one of my misfires that way - there was a hairline crack in the dizzy cap which couldn't easily be seen but in the dark it was like a laser light show!

Have just read your original post and it suggests fuel
vapourisation?? Has the problem eased now that the weather
is much cooler???