1968 Daimler Sovereign Auto Enrichment Device

I’m still learning about this car. I was at my storage over the weekend to start it and the previous owner has bypassed the thermal switch with a manual switch in the car. I can here a click when I operate the switch, so I assume the AED is working. The strange thing is that the car won’t start from cold with the AED operated (just cranks and won’t fire), but when started without it the engine runs rough and barely idles and I get the occasional backfire.
Is this the AED or just the carbs need setting up first and then look at the AED?

I have a workshop manual, but if I read it correctly, the AED is set up with the engine warm and I cannot get to that point!



You need to step through the basics of fuel /float level, jet height (mixture settings) timing etc first. It’s is most unusual for one of these cars to start from cold without the choke.

Definitely start with the carbs and then the ASC adds air AND fuel, so see if it gets fuel, otherwise it will make the mixture even leaner.
If the PO was absolutely incapable he may have screwed down the stop screw of the ASC needle, so if you have fuel screw that out a few turns and see if that changes anything.