strange...

how does it die? quickly shuts off or stumbles over itself and dies...

does it do it every single time, without fail, or is it just most of the time?
does it matter if you've been driving for a while or not?
What about load, if you creep up to 80 is there a difference rather than if you floor it up to 80? does it still do it going down a hill?

I know those all sound pointless, but it could help point to something...