My LC1 has stopped supplying info to the MSnSE. I have also now noticed that the LED is not illuminating at any time. Could this be that my LC1 system has gone wrong or is it something to do with the way that I have set it up? I should say that it has been working for about 6 months (1000 miles), the engine was running very rich and there is power to the LC1 controller.

Any ideas on the way forward?

im sure with my lc-1 kit i got a leaflet of things that happen to it when it goes wrong and it gave you instructions on how to reset it etc. did you get one of these? might be worth a read, im sure that the light flashes on warm up and then continues to flash rapidly if something is wrong, i cant remember exactly?

I cant help - but I hope some one can as mine has just started playing silly bugger's too - it keeps switching on and off while driving , which is making mapping kinda hard
And when it goes off (the LED goes out..) the gauge goes to fully lean , then fully rich when it comes back on - and if I give it a good thrashing it stops reading all together , and the LED flash's

Early LC-1's before the "lightening" box artwork were prone to failure and from memory needed a resistor in their power feed to protect them.

Have you tried seeing if it reacts for a free air calibrate routine?

Failing that, their forums may be worth a search.