Morris Minor Owners Club

Ideas please, sure you have herd it all before. 1098cc 1970 car has always gone like a dream for 8 years, admitt short runs now and again. Did 30 miles no probs, next day did 15 miles and on way home started to splutter then backfired then died, came back to life after a few minutes, ran a bit then died again and so on till got home.
Has had new fuel pump, new hoses, cleaned carb, new jet, new float, clened sooty plugs, oil clean, no mayo in rocker cover but a tiny bit in top of radiator. Got him running and followed carb set up for correct running but she still seems unhappy, OK but hesitates a tad here and there.
Could it be the head gasket I wonder? a bit scared to chance a good long run in case he dies on me again!
Any ideas gratefuly received.

Sounds more like an ignition problem to me - failing coil, condensor, rotor, dizzy cap, poor/shorted connections etc. Normal procedure is to first test for a good spark at the king lead when cranking the engine, but it is always trickier to diagnose intermittent problems so alternately I suggest swap one component at a time.

My intermittent cutting out and non start when it wanted to resulted in a faulty coil lead.

With checketd valve clearances, a compression test would reveal a head gasket (or valve-seating) problem. A check for ignition spark immediately, when the problem occurs, would confirm whether or not it was an ignition problem.

No point in changing everything without knowing unless you are happy to throw away money. The ultimate scenario of blindly changing parts is to replace the car every time a fault occurs!!

I would certainly focus on ignition system.. condensers make them do funny things when they're starting to break down. Make sure you get good quality stuff though - there's a lot of cheap rotor arms out there that actually conduct electricity and also dodgy condensers etc.

Biggles1957 wrote: ↑Sun Jul 07, 2019 9:47 am I would certainly focus on ignition system.. condensers make them do funny things when they're starting to break down. Make sure you get good quality stuff though - there's a lot of cheap rotor arms out there that actually conduct electricity and also dodgy condensers etc.

I agree. Condensor.

Thank you all for your comments.
I will change condenser and see what happens. Have checked points, leads, connections and distributor cap is quite new.

If you are going to change the condensor, I agree with 'Biggles1957' that you should get a quality condensor, and suggest the 'Distributor Doctor' for that. Whilst I agree with 'oliver 90owner' that methodical tests are the best way, it is not always desirable to run an unreliable car in the hope that it breaks down, just so you can carry out tests by the side of the road, miles from home, particularly when you say points, dizzy cap, leads etc. are all good, suggesting condensor or possibly coil or rotor problems. I always carry spare points, condensor, a (good, old) coil, rotor, dizzy cap and leads as insurance, but have never needed them after fitting components from the good doctor. To get a new, quality rotor and condensor at this point would seem sensible, just in case one of them is the culprit.....even if the car does die at the side of the road, it helps to have the right spares handy if you do diagnose the fault correctly. In the past I had exactly the same symptoms as you and it turned out to be a rotor that was breaking down - sometimes the car ran, sometimes it didn't.

Well I have changed the condensor for a spare I keep and also the rotor and bingo I think we have lift off!
Will take for a longer drive when I get a chance during the week. Will replace my spares SAP.
Thank you all.

That sounds encouraging and fingers crossed, though I doubt the condensor and rotor arm both failed together. Assuming all is well on your longer run, I would be tempted to then put the old rotor back and see what happens - if the engine plays up again, then it was the rotor......if not, then it was the condensor. And, once again, get the best quality for your new spares - in case your replacements have a short life. Poor quality condensors and rotors have let many a Minor owner down in the past......myself included

Will do, thank you for the advice. While in the mood going to flush the cooling system and then do some test runs with new and old rotor in place. I feel sure it was the condenser at fault. Think Morris was feeling neglected due to purchase of a new project and needed to remind me he is still here!!

Make sure that you throw the old condenser away or you could be refitting it in a few years and having the same trouble!!

Apart from the weak yellowish spark, the contact points can be burned due to excess arcing. Depends on whether the condenser is going open or short circuit, of course.