Starting help please

[geoberni]

Thanks for your reply. I maybe didn’t update the post properly. I was cold and a bit fed up in the garage by that point. I was getting 12V at the battery. 10V at the coil and then the draw down to 5/6V when trying to start. My multimeter then packed in so I put it away for the afternoon. Battery is off and on charge so I’ll have another look at it on Sunday morning. Thanks all.

So you're loosing 2v from Battery to Coil, which needs sorting in order to get anywhere.
But that 50% drop in applied voltage when cranking is indicative of your real problem.

I've just been out to my garage to put Basil's battery on charge for a few hours, which I do every week or so during the winter.

It's about 0 C in the garage still.
Battery showed 11.97V and before putting it on charge, I cranked it over, minus Ign supply, to see what the terminal voltage dropped to.
It dropped and stabilised at 9.38V, so basically it dropped 2.6V, a lot less than the percentage drop you had.

I suspect you have a poor battery and some wiring that still needs sorting out.

Simon has a good point about the Coil connections being appropriate configuration for the polarity of the Battery Earth.
See here: viewtopic.php?t=70183

[svenedin]

Halfords sell Easy Start but I’ve started a lawn mower with carburettor cleaner before…..

Stephen

[Dougie212]

Thank you all for your responses.

I’ve been out and got a can of easy start - didn’t work so it seems like everything, as you all suggest, is pointing to a wiring/electrics issue.

I’ve taken the battery off and put it on charge and will leave it until Sunday morning. The coil suggestion is a really good shout, I’ll try power straight to it from charged battery and see how it works.

The car is still positive earth so I will double check I’ve got everything as it should be. That in itself I’m a bit of an alien thing to me so having to work backwards to what I would normally wire is probably something I should double check.

Thank you all again..!!

[geoberni]

The car is still positive earth

In which case Connections are as per the wiring diagram :

With an Old Coil markings, it's SW to Switch, CB to Dissy.

With a modern Coil marked +/- that equates to '-' from the Ign Switch, '+' to the Dissy.

If any doubt, just do the Pencil Test described in the link I posted earlier.

[Dougie212]

Update this morning - so checked and rechecked my wiring. All as expected. Checked and rechecked spark… all good. Rechecked compression…….. then rechecked compression and noticed none on 2 and 4

Checked the valve clearances and clearly the rule of 9 and adjusting them messed with my head and I’d got a couple that were too tight. Adjusted again - this time holding the adjuster screw with my screwdriver while tightening the nut up. Compression on all 4…

Hey Presto… we have life!!

Thank you all for your help and suggestions. Always very much appreciated!

[myoldjalopy]

Coolio! And a nice, easy fix as well - we like them!

[simmitc]

Excellent news, well done, and thanks for confirming the root cause of the problem, it's always helpful to have the solution to help others in the future.

[svenedin]

Update this morning - so checked and rechecked my wiring. All as expected. Checked and rechecked spark… all good. Rechecked compression…….. then rechecked compression and noticed none on 2 and 4

Checked the valve clearances and clearly the rule of 9 and adjusting them messed with my head and I’d got a couple that were too tight. Adjusted again - this time holding the adjuster screw with my screwdriver while tightening the nut up. Compression on all 4…

Hey Presto… we have life!!

Thank you all for your help and suggestions. Always very much appreciated!

Great news. Next time you do the valve clearances leave the feeler gauge in place when you re-tighten the nut. Then you will immediately notice that you have actually moved the screw and you can’t remove the feeler gauge! I go round the valve clearances twice when I do the adjustments. The second cycle is just a check.

Stephen

[Dougie212]

Ahh yes, that makes perfect sense, leaving the gauge in place. I’ll do that. I’m doing the oil filter conversion next weekend so when I run it up again I’ll do this when I come to adjust them again.

Thank you to everyone for all your help and suggestions!!

[geoberni]

Great news. Next time you do the valve clearances leave the feeler gauge in place when you re-tighten the nut. Then you will immediately notice that you have actually moved the screw and you can’t remove the feeler gauge! I go round the valve clearances twice when I do the adjustments. The second cycle is just a check.

Stephen

I wouldn't ever think of removing the feeler gauge before tightening; that's really the point of doing the job, locking the tappet in that specific position. I doubt anyone could successfully adjust the gap and then be able to lock it off after having first removing the 'gap setter'.

To me that makes about as much sense as removing a ruler before drawing a straight line.... But I guess if you've never done such basic engineering before then 'you don't know what you don't know'....

[Bill_qaz]

Great news. Next time you do the valve clearances leave the feeler gauge in place when you re-tighten the nut. Then you will immediately notice that you have actually moved the screw and you can’t remove the feeler gauge! I go round the valve clearances twice when I do the adjustments. The second cycle is just a check.

Stephen

I wouldn't ever think of removing the feeler gauge before tightening; that's really the point of doing the job, locking the tappet in that specific position. I doubt anyone could successfully adjust the gap and then be able to lock it off after having first removing the 'gap setter'.

To me that makes about as much sense as removing a ruler before drawing a straight line.... But I guess if you've never done such basic engineering before then 'you don't know what you don't know'....

Agreed but Life is a learning curve and we are on different points.

[geoberni]

Agreed but Life is a learning curve and we are on different points.

It's all about the learning curve...
I know someone who is a skilled artist and produces wonderful pictures using pens and inks; but given a pot of paint and some decorating to do and they are terrible, laying the paint on too thickly, so that it runs and wrinkles as it dries....

[Bill_qaz]

It like the story of NASA spending lots of dollars getting a pen developed that could write in zero gravity. The Russian astronaut took a pencil with him.
Different strokes for different folks