Ty_bach

Thanks Paul, but what is the relay for, why must it be in the circuit? I understand the fitting of a relay when incorporated into e.g. headlamp circuit or a horn circuit, but I don't understand why the relay should be fitted into the ignition circuit as is suggested in this way. Apparently its only on +positive earth cars and not -negative earth cars. Why? Martin

Hi, For many years (35) that I have owned my Herald 1200 Convertible, when I have gone out in the evening or on a poor day, I have put up with juggling my power requirements between the heater blower, the wipers and the headlights. I can have two out of the three, but not all three turned on. The dynamo could not handle the load. I recently decided to fit a Dynamator to my +positive earth car. The supplier gave me a relay to wire into the ignition circuit. Can any one tell me exactly what the relay does as I don't see the point of doing so? Martin Herald 1200 Conv 1966

Thank you all for your hints and comments. Having gone through them, I did discover that the needle valve on the float chamber was stuck in. I unstuck it and made sure passages were clear and the needle valve worked smoothly. I reassembled everything and started the engine again. Good start but a few seconds later, it ran like a tractor or even worse and then died again, I was now getting suspicious that it was nothing to do with the carb but perhaps the ignition system. One of the weak links in the conventional ignition system is the condenser. So I decided to change it for a spare I always carry with me in the boot of the car. Bingo! the car started and ran normally. I took it for quick run round the block and it performed quite normally. Fiddling with the carb was not a complete waste of time since I took the opportunity to clean out the float chamber and check all the jets were free of dirt. Thanks again for your help.

Up to this week, the car has been running smoothly. Then suddenly overnight, I start the car next day and it will fire up , but won't keep going. the revs rise and fall very roughly with the choke either in or out and eventually it dies and you start over again. The engine starts easily but will not keep running for more than 30secs - one minute. Because of the easy starting, I am assuming its carburation. I noticed petrol was weeping from the accelerator pump so decided to replace the diaphragm, but that did not fix the problem. I have thought about water in the petrol but since it has been sitting in my garage for a couple of weeks and not been in the rain, this has been discounted. I have had all the jets out and checked. Still no improvement. Now running out of ideas.