Intermittent misfire

["Slack Alice" Simon]

If a tappet block has split, as per a previous thread, that might stick too.

[12jslater]

Had a good look at the valves today, very clean, and all seem happy, I don't see anyway they could be sticking, I've now ensured the points have a good connection and cleaned any tiny bit of dirt of any connections on the coil and points they are absolutely spotless there is no chance of a bad earth or a dodgy connection now (not that there was much of a chance anyway)

I'm wondering if there is anyway it could be the head gasket? Or even a crack in the head. Even though compression is absolutely fine and I have no signs of water in oil or one very steam cleaned spark plug haha.

Just a thought

["Slack Alice" Simon]

Try shorting out a plug whilst running, using a long screwdriver with an insulating handle.

Does the misfire stop when one particular cylinder is out of action?

[Colin Wilks]

Ay up young Jake. Have you sorted it?

Regards

Colin

[AustinWood]

When the valves in our car were sticking it was because of a build up of carbon on the stem.

[12jslater]

After the past week on and off trying EVERYTHING I can think of it might be something I have to live, absolutely nothing seems to effect it.

[Ivor Hawkins]

No one should have to put up with an intermittent misfire, regardless of the fact that it’s an old car.

Do you have any club members that can pop over and have a look? The problem is bound to be something utterly ridiculous!

[12jslater]

I know, however I suppose at least I have plenty of time to sort it seen as with all the covid nonsense I've managed to loose two jobs since march so the car as of two days ago isn't insured as I've no need to drive it nor money to insure the damned thing, I'll recheck EVERYTHING I can today which will be for around the third time haha 

Maybe by some miracle I'll come up with something

[Colin Wilks]

Hi Jake

This may be a completely bum steer, but it would be interesting to know exactly what you did when you cleaned the valves.
If you stripped everything and cleaned out the valve guides they shouldn't (!!) be the problem, but if you cleaned the valve chest and inlet/exhaust channels in the head with petrol with the valves in place the petrol will carry minute bits of crud down the guide and then evaporate leaving the crud in place.

Petrol is good at doing this. To get old engine oil well into the leaf springs I dilute it with petrol, which carries it right in and then leaves the oil behind.

I'm sorry to hear about the jobs. I'm well into retirement so the realities of life for working people tend to pass me by. Probably no great solace to you just now, but things will get better!

Good luck.

[Andy Bennett]

The one thing that hasn't been mentioned is the coil itself.
Would be worth swapping out if not already done as internal breakdown when hot would not be the first and it's easy and cheap to find out.

Also lots of examples of coil problems being discounted because replacing it makes no difference, only to find that the new one is of poor quality and also faulty, so definitely worth swapping with a known good one.

Also make sure it is wired correctly. I ran mine for years before realising it was wired the wrong way around and produced a stronger spark when correctly wired.

Andy