Avdr thanks for the reply and perhaps I should have said " three distinct steps and everything in between ". Of course the opening of the throttle is gradual and I would expect everyone on this forum to know that, but thanks for pointing it out. Today I looked at two different cars and the way they ...

Thanks Ant... Yes all signals checked at ecu multi plug...

The way forward may be to get my hands on a known good Astra and carry out some tests on the system.

Thanks again Paul88

Thanks Ant and Robski for the response... Good answers (They make good sense) So if we follow the theory through... I now need to know why is the ecu commanding the throttle to close ? Is it responding to inputs from the vehicle i.e accelerator pedal or is it a faulty ecu. The pedal potentiometer as...

Liteace the background noise is the throttle banging shut. The ecu is commanding the throttle to close, when it should be commanding it to open. In response to the pedal being pressed. The two wires that run to the motor from the ecu can be seen on the scope screen as blue and red. If you command th...

Thanks Matt I will download demos and give them a try. I think I met you recently on the Pico course at Preston Lancs, and is it the same Matt who's working on the wavehook site???
Thanks Paul...

Can Pico recommended any particular software for uploading labeling and animating waveforms?
Paul...

Matt thanks for the assistance, turned out to be a printer fault. Pico performs perfectly.
Thanks Paul..

Matt
On laptop screen, channel A is blue ( Primary ignition waveform ) Channel B is red ( Primary current waveform ) I then click file and save current waveform. It is saved in two colours, but when I print, both waveforms print in red.....
Paul..

When printing a waveform using two channels should the print show the channels in the two different colours or will it be in only one colour.
Paul...