First thing is to check that actual pressure (measured with gauge) is the same with pressure sensor value in diagnostic tool.
That is the problem, I could not see a PID for Fuel Pressure, neither Actual, Desired or ECU Duty to PEM using KTS. Next time I will try Snap On or Autocom. We will see ?
Control signal to fuel pump should also be PWM between 0 and 12V. I don't like 2V range you have.
Alas we agree
Indeed with the car running (alternator charging at ~14v) with the Volt Drop on the Positive Side (nearly 2v) that wire is still carrying 12v loaded with the pump and a 21w bulb. With the Earth switching at 2v, that is still 10v (12v minus 2v) potential difference at the pump at 83% duty.
I did look at Injector durations. I expected to see 2.6 - 2.8 (from experience - not technical data) and they were steady at 2.1ms. Although I accepted that figure as ok at the time tied with it being in "Closed Loop" and Lambda switching between 0.98 - 1.02.
Assuming my expectations were right or close, we have more evidence that Fuel Pressure is higher than desired and the Controller is able to keep Lambda happy by strangling the Injection events.
Measure pump power and ground at PEM and add current also and post here.
My Customer has sourced a used PEM which will arrive in a day or so. When I go back I will first test to confirm the ground wire to fuel pump is not shorted to ground or contaminated.
I have a feeling it will get fixed next time. I can smell it in the air
Then I will get Before & After Captures, Post & Upload to Library.
Thank you for your help, advice and information.
Will update soon