Morris Minor Owners Club

hi all,

I'm not sure if i have a problem or not, and i'm resistant to tinker until i get some advice as the car is used everyday.

I was travelling back to london from bristol on saturday night and decided to nip down the m4. got onto the motorway which leads to the the motorway, but i found the engine was missing beats about every ten seconds. It was still making the 65/70 i normally do, but would just jerk slightly and then pick up. It was just like the engine vanished from the drive for a split second.. quite un-nerving.

So motorway abandoned, I came back the slow way through the country. I managed to pull over and checked the gap (0.4mm) and sprayed some wd40 in the distriubter (altho i'm not sure why i decided to!), and i checked the leads were tight (they were i think). the problem did not return, and i made the 65/70 mph on the way down, and also on the m3 which i use for a brief stint, without problem.

that leaves it like this.. i had a problem, now i don't, but i can't think that my roadside fiddling could have resolved it! could it be the timming.. i've never done it in the 18 months of owning and i have changed the points and adjusted the gaps. I was wondering if it could be this as i'm sure the old girls struggling more than she used to... or was it just a hot day and the fuel playing tricks (think it was 20c that day).

all help very gratefully received!

James
I would have thought "timing issues" were unlikely from the symptons you describe.Loss of power.. due to timing would be a permanent problem , not intermittent.
Electrical. ?..could be the condenser on it's way out .Inside the distributor ...is the rotor arm clean on the contact point and ditto are the four contact points, for the HT leads, clean and not corroded ?
Spraying WD40 in the distributor is not a good idea.You can spray onto a cloth to wipe the inside of the distributor cap to clean and weatherproof it.However flamable WD40 fumes/ liquid mixing with electrical sparks inside the distributor could result in a bit of a bang !! Following the bang,lack of foward motion would result and a new distributor might be required. Loose low tension wiring unlikely on a smooth motorway but more likely dirt in the fuel supply.Did you fill up at a different petrol station, to your usual one, prior to setting off ?

When the engine is cold, rag underneath the carb, carefully remove the three screws holding the lid of the carb float chamber down.Lift the lid carefully so as not to tear the delicate paper gasket and see if there is a lot of dirt/ sediment in bowl.Clean out...paper kitchen towel/ non fluffy rag moistened with some meths / carb cleaner.

Whilst " in there" examine the needle / float arm.Check that the needle is clean...no specs of dirt, not worn...small ridge can be felt with a finger nail...the "cone" should be smooth to shut off the fuel when float is raised.Check needle is free
to move up and down unhindered.The hinge on the float arm should also move freely.The float level should be OK if you have had no trouble in the past 18 months of trouble free motoring.

Replace lid carefully, not damaging the gasket, and tightened screws down evenly.Remove rags.
Good luck with your investigations.
Bob

about every ten seconds

This sounds about when I'd expect the petrol pump to be pumping at that speed.
I'd check the filter in the pump, that the hole in the petrol tank cap is clear and the filter on the petrol pick up in the tank, in that order.

This sounds a bit like the problem I had with my old traveller before it finally conked out! The solution: a new rotor arm.

I have had similar problems with substandard parts on my Midget and now carry spare condenser, points and rotor arm at all times. (you may recall correspondence in Minor Matters some months back on rotor arms). Do also check the dizzy cap as they tend to break down after a while.

First of all though, I agree you should check that you have a clean fuel supply - clean the carb and filter in the fuel pump. If your tank is a bit old and therefore rusty you may want to put an additional in line filter in the line before the carb. Modern petrol contains ethanol which is not friendly to old petrol tanks and if you have run it low enough to suck up some crud at some time then that could have caused your problem.

Let us know how you get on.

Chris

thanks for all the suggestions.. I thought the rotary arm might be a possible cause. I've got plenty of spare so i think i'll go for a new one and a new condesor asap. I also had to run the tank quite low recently, so crud is certainly a possibility. also had to fill up at the evil tescos so my car's probably had just about enough of me of late, and has taken revenge!

I'm not tinkering until monday, as i've got a wedding to get me and the misses to this weekend. I can't imagine she'd be to happy if i messed the carb up.. a seat belts already gone duff on me this week!

on the upside.. its not been playing up since then (apart from rare cough) and the car's sporting new carpets and underlay, the interior floor has been derusted and painted an attractive rust proffing grey, and finally the speakers are in recessed in the front panels (and gaffa taped to the dash board underside!). not to scruffy for two days work

You fixed it with your roadside repairs - it was probably mild 'tracking' on either the dizzy cap or the rotor arm - the WD40 fixed it for you! Well done. It's highly unlikely to 'explode' - I bet in a hundred attempts it still wouldn't explode. And even if it did - it would be the smallest 'explosion' in the world........By all means try another rotor arm - and / or another dizzy cap, but don't get drawn into a list of 'fixes' that your engine doesn't need! Si fractum non sit, noli id reficere........