The V8 Owners Forum -

Sounds like the coil is breaking down when hot or working hard.

Denis

Engine starts and idles o.k.
Runs well initially
Car will pull steadily but open the throttle fully and it loses all power, misfires (?) untill you come back off the throttle.
After the car's run for a while it cuts out and dies, leave it a while (cools down ? ) it'll start and I can drive off
New 8mm ignition leads, different fuel pressure regulator, still the same
Any ideas ?

Measure fuel rail pressure. Maybe with the readout inside the car so you can monitor whilst driving. I have used an oil pressure gauge on a long piece of pipe to do this in the past.

Chris.