Won't start

[Nickol]

Thanks ever so much for both of your inputand, the Mgb -stuff especially is a great help.
Definately an insulation breakdown and I have been playing with the set up at my desk. I can get proper dis-continuity when levering the spring a little and now I notice, there is no fibre washer under the pivot post. That would explain the short circuit and is easily solved.

And yes, MyOldJalopy, I do believe you are right in that the intermittant problems before have a root cause which I would like to get to the bottom of.

[Nickol]

Worth checking the low tension lead. It can short on the distributor baseplate if the insulation has broken down.

For illustration: https://www.holden.co.uk/p/low_tension_ ... _connector

Stephen
[/quote]

This piece on my Distributor does look quite good and as per my post above, I am hopeful to have found the cause of the insulation breakdown. More tomorrow.

[svenedin]

Worth checking the low tension lead. It can short on the distributor baseplate if the insulation has broken down.

For illustration: https://www.holden.co.uk/p/low_tension_ ... _connector

Stephen

This piece on my Distributor does look quite good and as per my post above, I am hopeful to have found the cause of the insulation breakdown. More tomorrow.
[/quote]

Great. Yes no insulating washer (whether plastic or fibre) under the contact breaker spring-arm will cause a short to earth.

Let us know how things go with new points and condenser. A failing condenser can cause intermittent ignition problems.

Stephen

[Nickol]

I remember ,Steven, in one of your posts that you remarked that to start your Minor from cold you just pulled the choke fully out and the engine started straight away.

This afternoon I reassembled the Distributor points as per the MGB-stuff and with the fibre washer underneath. As the base plate was not disturbed, the points gap did not need resetting and checked out ok . 0,4mm. I then checked the continuity. Strangely there was non across the closed points so I used some rubbing paper that looks like emery but is not. After that continuity with closed points was re established. It is often said with new points you should do this and this is the reson why.

Refitting the distributor is a pain. Getting it in position is ok but trying to put in the retaining bolts is problematic! Whilst it was out and before refitting I took the opportunity to clean the whole area of the engine and chassis. The oil feed pipe from the filter to the block obviously leaks at the connections. It needs replacing I think, preferably with a flexible one.

Anyway, the rambling of the above, just to keep you all in suspense, had a happy ending (so far) ;choke pulled out, key turned and the engine immediately sprang into life. The carb needs adjusting and perhaps the timing too , but it runs!

[myoldjalopy]

Good news!
Now that you have stopped the points shorting out, it is possible (fingers crossed) that the new DD condensor may have eliminated previous issues. Drive it and see how it goes.......

[Nickol]

Certainly the engine starts from cold without any problem which is very good and a great relief. I cannot get however, get the choke mechanism to cancel completely. i.e after pushing the choke in and then going under the bonnet, I have to manually push the the choke underneath the carb a little bit upwards to close it. It will not close on its own. Perhaps with usage and lubrication this problem, if it is a problem will solve itself.

The engine does not idle evenly which could be a number of things. I will sort these out in the next few days.

[Bill_qaz]

Yes, that appears to be working as it should but sometimes it did stick and not return properly which meant an overrich mixture and fast idle. Not releveant for a difficult cold start though. I have given it all a good clean and lubrication.

As ever, will wait overnight and try again tomorrow and report.

You quoted this issue earlier on
Have you tried disconnecting the cable, so as to work out if a linkage issue or the cable itself?

[Nickol]

that is old hat now - but yes, I have disconnected the linkage to see if this was the cause.

[Bill_qaz]

that is old hat now - but yes, I have disconnected the linkage to see if this was the cause.

It was in response to your latest post on Monday, when you said choke not going fully off. I just meant has this issue resurfaced from earlier in the discussions?

[Nickol]

OK I understand now!

I have, during the winter renovated the carb , cleaned it up and replaced some of the parts. So it looks nice and works a lot better than before - e.g the piston moves quite freely , which in retrospect I am sure it did not do before. Perhaps the locking nuts are too tight? Anyway, the choke at the moment needs to be manually pushed home under the bonnet - it is only about 1 or 2mm so may not be significant.

I had a "play" with the timing on the distributor , firstly setting it too retarded but corrected that very quickly. I am just so happy that the engine starts from cold with no problems at all now.

So, not a big deal anymore. I am going to put new plugs in as the existing are a few years old and do an oil change.

[Nickol]

I thought I might make a further comment on my problem with the cold start as I made a few more adjustment since April which have resulted in much better running and starting.

I purchased a digital 5568 strobe light from Equus ( I think it is marked under another name in UK) and what a great tool it is! Firstly it was possible to accurately set the points gap due to its ability to measure the dwell angle. This took a bit of fiddling to get right.

Secondly, I set the TDC looking underneath the car and then placed a self made pointer held on with neo magnets so as to be able to see it from above and marked the pully with a white flash. Using the strobe, the idle of the engine did indeed show 4° BTC in operation. However at 2000 revs, it showed about 37° advance - Way too much. I turned the distributer to get the correct adjustment. I find this a bit strange as the static set up should for my logic be sufficient.

The engine has never run better. There is no longar any cold start problem.

I did do a very stupid thing though. To access the loosening nut for the distributor ( I use the ratchet and extension rod) I removed the dipstick but forgot to replace it when doing the test drive. Oil everywhere!

[svenedin]

I thought I might make a further comment on my problem with the cold start as I made a few more adjustment since April which have resulted in much better running and starting.

I purchased a digital 5568 strobe light from Equus ( I think it is marked under another name in UK) and what a great tool it is! Firstly it was possible to accurately set the points gap due to its ability to measure the dwell angle. This took a bit of fiddling to get right.

Secondly, I set the TDC looking underneath the car and then placed a self made pointer held on with neo magnets so as to be able to see it from above and marked the pully with a white flash. Using the strobe, the idle of the engine did indeed show 4° BTC in operation. However at 2000 revs, it showed about 37° advance - Way too much. I turned the distributer to get the correct adjustment. I find this a bit strange as the static set up should for my logic be sufficient.

The engine has never run better. There is no longar any cold start problem.

I did do a very stupid thing though. To access the loosening nut for the distributor ( I use the ratchet and extension rod) I removed the dipstick but forgot to replace it when doing the test drive. Oil everywhere!

Well done! It is possible that your distributor was not intended for your car and is another Lucas variant for another BMC car. Or maybe the springs inside are old and weak and it now gives excessive centrifugal advance. In any case you have sorted things for now. The distributor can be professionally rebuilt and calibrated to the correct advance curve but this is an expensive undertaking.

Stephen

[Nickol]

Thankyou Stephen for that - definately worth thinking about although I have checked already some time ago that the distributor is the right one a 25D2 or whatever ( going from memory) . I think I will get it calibrated , probably by the excellent "doctor" but only when I next visit. He did my Triumph Herald one a few years ago and what a difference! However, that was pre Brexit and nowadays the customs is just a pain and delivery takes a lot longar.
Interestingly from videos, I see that the position of the bellows pointing almost upwards in all of the minors, and mine previously did not.

Another coup today - I found the cause of the rattle at the rear end - the bolts for the right hand shock absorber had worked loose. So wonderful now, driving on uneven roads with a smooth running engine and no clonk clonk from the back. Happy days!