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Re: 1936 Austin Ruby Misfire

The car seemed to be running fine when I put away after a short run.

It wasn't until the next time when I tried to use I it that it had developed a misfire, which is there all the time at alll revs.

Re: 1936 Austin Ruby Misfire

If you can, swap out the entire distributor for one known to be OK.

Also, try filling the float bowl with fresh fuel to eliminate possibility of duff fuel in the tank. At the same time check the jets are clear.

Check for air leaks round the carb manifold joint.

Location: North Herts

Re: 1936 Austin Ruby Misfire

Is it general or can you pinpoint one cylinder by taking off or shorting plug leads?

Simon

Location: On a hill in Wiltshire

Re: 1936 Austin Ruby Misfire

You say the car was put away after a short run, but not how long ago that was? If it was a while, a fresh fill of petrol may be the answer - it can go off from one season to the next.

Re: 1936 Austin Ruby Misfire

Nick, The fuel is new in the tank is only a month old.
I will check the jets in the carb.
As far as the distributor is concerned, it does have a slackness to it, in certain positions, do you think it could be that, thats causing the problem?


Re: 1936 Austin Ruby Misfire

The car had only been stood for 4 days.



Re: 1936 Austin Ruby Misfire

Simon, after removing the plugs from running the engine, 1 and 2 looked wet, 3 and 4 looked very sooty.

I did remove each plug lead while the engine was running, and in fairness they all looked to be working okay.

David

Re: 1936 Austin Ruby Misfire

Have you tried swapping over the sooty plugs for the wet ones to see if the wet/sooty problem moves cylinders?

Is the carburettor flooding because over rich running will cause the plugs to soot up and eventually fail (hence the wet ones)

A worn distibutor shaft will cause erratic running as the points gap will vary. I had a similar problem until I changed to a Bosch from Willie McKenzie.

Have you tried a set of "hotter" plugs?

Re: 1936 Austin Ruby Misfire

Not sure what you mean by 'slackness'. There are several bits of the dizzy that can wear/misbehave but a sudden occurence of a misfire would suggest something has broken/given up the ghost.

Could for example be a crack/short in the baseplate. That's why I suggested a swap if you can find or borrow a known good one.

You could also try running the car when it is getting dark and having a jolly good look round the ignition system. That can sometimes reveal a short sparking somewhere it shouldn't.

Location: North Herts

Re: 1936 Austin Ruby Misfire

Nick Salmon
.

You could also try running the car when it is getting dark and having a jolly good look round the ignition system. That can sometimes reveal a short sparking somewhere it shouldn't.


Great minds think alike! A friend of mine had a misfire on his Austin K7 lorry. We ran it up in the dark and it was easy to see there was a short in one of the HT leads. They had screw on ends. Re-did the end connection and all was well. It took us a couple of hundred miles around Normandy and few tanks of fuel to finally get rid of the sticking brake problem though.

Location: Essex/Suffolk border

Re: 1936 Austin Ruby Misfire

Apologies, it was a K6, as can be seen here:

http://miliblog.co.uk/?cat=102

I hope you get it sorted. I would still look at the rotor arm, particularly if its a riveted one, as it could be showing early signs of failure.

Location: Essex/Suffolk border

Re: 1936 Austin Ruby Misfire

Nick, Slackness i was referring to was the fact the rotor arm can be twisted back and forth as if the drive gear is a bit worn.

I will try running it in the dark to look for any sign of external sparks.

David

Re: 1936 Austin Ruby Misfire

Thnak you for the advice on the rotor arm, I did fit a new one, when I replaced the distributor cap..

David

Re: 1936 Austin Ruby Misfire

Some good advice.
The carb does drip fuel from the air intake area for a second or two, when you stop engine.
It has had a new needle valve and floot fitted recently to try and cure this, but with no success., I was considering fitting a fuel line pressure regular to see if that cures this problem.

David

Re: 1936 Austin Ruby Misfire

Out of interest, have you found the cause yet David?

Location: North Herts