Can anyone help with a problem on a Toyota Avensis 1.8 1998 eng 7AFE. Car runs fine when cold for first 10-15 minutes and then starts to misfire, first at higher rpm 5000 plus and then at lower rpm after a couple more minutes, but never below 3000 rpm. It will run fine below 3000 rpm until its been running for a good half hour and then it will cut out and won't start. After waiting for about 5 minutes it will start again but will not rev much more than 3000 rpm. When it reaches 3000 it sounds like it is hitting the rev limiter.The most noticable thing is that the injectors stop opening but the ignition sustem along with all the sensors are affected. A friend put his Pico Scope on it today and said the earth to cam crank coils injectos were spiking. we tried putting extra earths in places but this did not fix the problem. The ECU has been tested and said to be Ok.When it cuts out and won't start there is no signal from cam ,crank ,injectors and no spark. Can anyone suggest what to do next.

Chris