You should definitely stop the PowerFC from running in feedback mode.
Now that sounds a bit technical for me Rob, can you explain further please? Do you mean just turned off whilst the problem with the vems is resolved as it is providing the signal to the Fc?
In a nutshell, Yes.
Quote below from the power Fc page for the ECR33 skyline
"If you have 0/2 Feedback turned off the PowerFC will not enter its closed loop feedback mode and will waste fuel and be very un-economical. Expect bad fuel economy"
This will be only at part throttle and low RPM - such as when you are cruising. Once things get interesting the ECU will go out of feed back mode. Lambda sensors came about so that
catalytic converters would work, the newer wideband ones are an evolution as a result of greater emissions control.
Ps, the new sensor I've just got gives exactly the same irratic readings when the ignition is turned on but not the engine running so i'm going to bet the one i've sent you is fine..
The vems unit is making a charging type sound going up in pitch then down then up is this normal?
Yes, it reminds me of the noise you get when a camera flash is charging up.
Also i've just noticed as soon as the ignition is turned on the gauge flashes "E" for a split second before going to warm up mode "H" and it doesn't seem to show a lamda reading only an AFR and under that a 4 digit reading ? again is this normal?
That seems wrong, it should be H first and then jump into a reading once the thing is hot, this really sounds like the one I put on an engine dyno where the action of clipping and un-
clipping the sensor caused a wire to come out.
While this is not an impossability, it's very uncommon for a gauge to break, the ones that fail do so on their first test. But the fact that the reading is rubbish while you're
pressing the button seems way too strange.