Morris Minor Owners Club

Hi All,

Lots of suggestions here, thank-you! The engine seems absolutely fine (if running a little rich) for short journeys, It got me to Cardiff without issue, it was the return journey that caused problems. It seemed to start under load on the motorway, and improved when i reduced my speed down to 50 (i usually travel somewhere between 55 and 60). There are some monster hills on the M4 in south wales, and those are what upset her I reckon.

THe discussion so far seems to be entirely around the ignition side, could it be a fuel fault?

Thank-you!

As you describe it now - yes - limited fuel flow could be the problem. Do a test on the pump - it should pump 1 pint into a tin in under two minutes. Have you checked the air cleaner is pointed at the exhaust manifold?

Hi, I have an aftermarket (I think it's Marina) air filter on Florence, (not installed by me) so I can't actually move the inlet pipe for the air filter.

FURTHER DEVELOPMENT TODAY

I took her into a local garage near where I work. We found that the condenser screw was not fully tightened, and so we tightened that up. We also made sure that the vacuum advance was fully tightened and not letting any air out. We also adjusted the mixture slightly so the engine idled a lot happier. I thought this may be the solution, but OH HOW WRONG I WAS. She will fire relatively smoothly at idle now, but as soon as you try and move away, its almost as if the whole car has someone pushing against it, the other way, after a second or two, the car will then accelerate. If you pull the choke out when stationary, the engine splutters, misfires and tries to cut out and when travelling say, at 30mph when you need little effort on the accelerator, the car feels like she wants to cut out, meaning you have to drop down a gear to keep the revs up.

We've done the fuel pump check before and it throws a pint out in around 70 seconds, so I don't think the problem lies there.

In summary,

engine fires okay on tickover
engine fires reasonably under load
engine tries to cut out if choke is pulled out when stationary
HOWEVER if you pull it out further it fires fine (but obviously very fast)
Engine struggles to pull the car away from a stand-still for the first few seconds, but then is fine (it genuinely feels like there is a delayed reaction on the accelerator cable)
I will mention that my accelerator spring snapped (right at the end) not so long ago, but I managed to bend the next coil in the spring to make it work again (I only shortened the spring by one coil, so I can't think this has caused too much of a problem)

parts;
Points - NEVER CHANGED
Coil - NEVER CHANGED
Carb - NEVER CHANGED - But adjusted in the past
CONDENSER - NEW (upmarket £7 one from ESM),
PLUGS, LEADS, ROTOR ARM - All new (good stock)
FUEL PUMP - New in 2013 (not fitted by me) but still seems in good health.

I'm at a loss. Ha!

It may be running very weak. Has the idle mixture been set up correctly? Is the carb piston free to rise and fall easily - with a nice clunk - and is there some oil in the dashpot? Is the vacuum advance working ok - suck the pipe and watch to see if the baseplate in the dizzy moves back and forth. Have a good look at the 'low volts wire' in the dizzy - it may have frayed and be breaking contact when the baseplate moves - as you try to accelerate the car.

Have you changed the air filter yet..I thought my mini engine had died as it gradually got slower and ended up only crawling along, then found the exhaust had a slight leak and the air filter was completely choked with carbon?

Taupe

On the base of the carb ,you will find a large nut with a spring above it ,this is screwed up into the carb body,and holds the jet.Screw this nut right up into the carb,it will move just by finger pressure, until it will go no further. Then screw. back out/down counting 12 flats of the nut .This is the basic setting for the carb.Start up and let it get warm/hot... then on the side of the carb you will see a small pin hanging down. With your finger push this pin up until you feel slight pressure ,then just lift it a bit more,just a bit,if the engine stops,too weak,turn the big nut down a bit ,say half a flat. If on first attempt engine speeds up AND STAYS UP too rich screw big nut in/up a bit and try pin again .


You are looking for ........when you lift the pin for the engine to speed up but then Slow back slightly and sort of falter when the pin is held up.After each attempt you will need to just blip the throttle slightly to clear its throat so to speak.

With the engine off, On top of the carb is a plastic nut ,unscrew and lift there will be a long rod with a small plunger on the end lift it all out , and then drop it back in and push down on the black screw you should find that there is a lot of resistance and needs a good push to get the plunger right back in. If it just drops back down then you need to put a SMALL drip or two of clean oil into the top of the carb where the plunger goes TRy this and report back

Did you fix it - what was the problem that caused your misfire when hot ?????

Again - another 'endless' thread .... oh dear.....