Morris Minor Owners Club

My old points that came with the car from before the restoration finally wore down so much that no amount of adjusting would make them open. They were also very pitted so I fitted a new condenser with the new points.
First the problem was that the terminal on the new condenser was longer so when the distributor was advanced it would get stuck against the cap and the car would stall. Obviously nothing would look amiss under inspection so it took me quite a while to figure it out and bend the terminal.
The distributor was also loose so I turned it to get the car idling really well, then back just a bit (with the vac advance attached) and then the car worked OK but with some hesitation and stuttering on partial throttle (no knocking).
Took it out for a longer trip just today and it started to stall after about 5 miles. Disconnecting the vac advance fixed the problem so I'm guessing I had it set up way too forward but then why the nice idle and no knocking?
My vac advance unit is a NOS Lucas I got from another distributor (not sure for which car) but I wouldn't think it could be THAT different from stock as to cause such big problems.
I really want the car to work how it was designed to so I'll probably turn the advance back a bit. Hopefully I didn't ruin anything from having it too far advanced.

Set the points with feeler gauge and then set your timing with a strobe light. If the car pinks then retard a little.

Don't just rely on the rough and ready "best idle" method, this is not the proper way to set the timing!

If base timing is too far advanced the starter will have trouble cranking the engine as it will be fighting the expanding combustion gasses.

'Best idle' is BY FAR the BEST way to set the timing! A strobe light - what will you set it to???? Some random setting from 50 years ago - when the fuel was a very different beast to the pump fuel we get today ?

First of all, thank you all for your responses, the faults happened while going out to a nearby town for the weekend so I vented my frustrations from there after a slow and eventful trip with rain starting right the moment the car began to give trouble.
Managed to get home OK with the vaccuum advance removed and finally had time and tools to look into this better and the problem seems to come from several reasons.
1. The nut that prevents the distributor from turning needs to be VERY tight in order to work. The plate under the distributor begins to get warped before it can't be turned relatively easily by hand.
2. I had mistakenly set the points gap at 25 thou, not 15 thou, by confusing it with the spark plug gap.
3. The battery is new and the carbons on the starter are new as well, along with the cables so it turns very strongly on even a mistimed engine.
I've now set the timing, with a strobe light and also by listening to the engine, especially at about 1/4 throttle since that's where the car had the most problems. The manual states 6deg BTDC but I found the car would stutter under partial throttle at that setting, so I had to turn it back to about 4.5deg and now the engine feels very strong on partial throttle (test drive to confirm will have to wait until tomorrow). However, the idle is now very slow without having moved anything on the carburettor although the engine does not stall.
I haven't checked the advance springs yet but those might have become too soft, as the advance does rise very quickly as soon as the engine is accelerated a bit.
Best fuel I can get around here is 91 octane (not sure if the measuring sistem is different from the UK's though).
And on another note, I know it's never the coil but I did take a look to my engine running in the dark the other night and it looks like a disco in there. Main offender is the coil with sparks flying from both the positive and negative leads towards the center. The spark plugs also light up, primarily #s 2 and 3 but new ones didn't make any difference.

Hahahahaha - you can't blame 'the coil' if it's dirty externally. Give it a thorough clean, same with the plugs. You obviously have a good strong spark - so 'the coil' is working well! The tiny difference between 6 and 4.5 advance is hard to accept.... You should have a look inside the dizzy and note what advance (degrees) is noted on the bob-weight, and also to check that the springs are still connected - and indeed that the the bobs are free to swing. Then check that sucking the vacuum pipe actually moves the baseplate - and then it pulls back when you stop sucking! With that super low octane rating - watch out for pinking!

Dirty coil, me?[frame][/frame]I will admit I'm better at getting things to look nice rather than work properly, still, I'll clean with a little WD40 but I don't think the sparking will go completely away.
There was actually quite a difference in how the engine ran at 6 degrees and 4.5, but I'll have a look inside the distributor like you say to make sure everything it how it should be.
Still haven't done the test drive to check if my tuning worked since the parts I needed for my other project just arrived today so I was quite busy with this...[frame][/frame]And yes, the next step now is... Setting the timing!

Hmm - now that's VERY clean!! Well - it's possible that the coil cap has been damaged by tracking and has microscopic 'cracks' in the surface - allowing the sparks to escape. I must admit to not having inspected my engine in the dark - perhaps I should! You sure the sparks are from the coil - and not the brushes in the dynamo sparking away?

Spent many hours looking at tracking on my old Bentley in a dark garage. Turned out to be electrical resistance (due to an incorrect dissy cap, 30 degrees out in my case) manifested in leads breaking down, rotor arm burning out, tracking down the dissy cap etc.
Don't want to complicate matters but I agree 1.5 degrees isn't the problem.
Good luck! (I am embarrassed and off to clean my engine....)

Yes, the strobe light IS a good way to set timing! I have set my traveller like this and it was fine even with modern petrol.

Fine - but not necessarily the BEST !

Much better than guess work "by ear". And once you have set the timing by strobe, if it does pink due to fuel, just retard.

Better still -advance till it DOES pink, then retard slightly....I've had a strobe for 45+ years and never had to use it yet!

This ones turning into another Steering Wheel Nut debate.....

What's up with steering wheel nuts?

Internet was out, still haven't had a chance to look inside the distributor but I fear I might need to.
Drove the car today, started out fine but after about an hour (city traffic) it began to have very loud explosions when engine braking and then would stall, only to restart fine on the first try. My first guess was that the distributor might have moved but later checking showed timing was exactly as I had set it and only the points had gotten a bit close (around 10 thou).
Gave a good thorough clean to the cable ends to ensure a good connection and again seems fine in the garage but will need to take it for a drive to confirm. If there are still problems I suspect the bob weights or something restricting the base plate movement although sucking on the vaccuum pipe does move it quite a bit, maybe it's snagging somewhere.
Distributor cap is original Lucas from before the car's restoration so at least 20 years old although not worn, might try another one if I can find one around.
Here's a picture I took of the coil, most of the sparks are from the two side terminals (which I've covered in shrink tubing) towards the center. The brand new Champion spark plugs I've got on also light up occasionally.[frame][/frame]My Austin Healey steering wheel nut, now THAT's just working flawlessly!

I have finally solved the riddle!!!
Everything looked fine inside the dizzy, not sure about the two different springs but that's how the car came so I'm guessing they're correct.[frame][/frame]And as for the cause of the problem, part of it was this:[frame][/frame]Look at that low tension lead, I used that nice thick cable so that it would conduct electricity very well and indeed it did, but I did not take into consideration that the thick lead restricted the movement of the points plate, so now I replaced it with an adequate soft cable.
Adding to the problem was that the mixture was set a bit rich and I also think there might have been some junk on the carb needle. I weakened the mixture by two flats, then revved the engine up a bit with the choke all the way out to remove the junk on the needle and on the last test drive the car is now performing flawlessly, although just a tiny bit sluggish.
My plan now is to keep it as it is, advancing the timing by 5 clicks between drives until it's just how I want it; then I'll check the timing with a strobe and probably engrave it on a plaque or get a tattoo with it or someting.

The solid wire was definitely NOT a good idea. The thick/thin springs are fine...I can't quite make out the mech advance number - is it '13' ? Which is fine = 26 degrees mech advance.