Hi Nigel

Is it possible that you could take a scope capture of ignition primary & injector voltage with lots of time on screen & the sample rate turned all the way up.

This way you you could monitor what drops out & when (in great detail). If neither ignition or injection drop out, then maybe fuel pump current could be monitored??

Dont be blinkered into just taking the "classic" 1ms/div injector or ignition captures, when Pico is capable of displaying great detail with long time bases set.

here is an example....

http://www.londonroadgarage.com/images/secondary%20trigger%20lead%201%20vs%20primary.psdata

Use pico to establish what falters first & then set about finding the cause.

Regards

Dave