Racer74

Hi all,

Apologies first of all, I'm an interloper with an S1 Elise 111s and this is a lengthy first post! The 111s shares the same engine as the MGF VVC so any thoughts are welcome on the issue below.

I have an issue with the cars emissions; it idles and drives perfectly but the engine's running rich with tell tale smell and black exhaust deposits but no smoke.

Pscan has highlighted the lambda sensor is inactive and remains that way. The lambda voltage is mostly static at 0.49v with an uplift in voltage only when on the over-run from c. 2,500rpm where it will briefly climb to c. 0.6v before falling to 0.49v again.

Measuring the output from the lambda using a digi multimeter shows an output of c. 0.8v which does vary a little with engine speed, I think this is telling me the lambda knows the engine is rich but the ECU is not responding to the lambda.

Prior to me owning the pscan the lambda, temp sensor, air temp sensor were replaced recently with genuine MG ones to try and address the issue so I'm reasonably confident they should be OK.

The harness has good continuity all the way back from the various sensors & lambda connector to the ECU (+ve and -ve) yet the ECU appears to not respond to the lambda. I've tried a second hand Mems 2J to rule out the ECU but no change to the lambda response.

A couple of questions:

1) Would anyone be able to share with me some baseline 'live' Pscan data for the VVC? As a newbie to this type of diagnostics it would be helpful to verify I'm interpreting the readings from all of the sensors correctly and importantly to understand what I should be seeing for the lambda, MAP etc.

2) Does anyone know if the Mems 2J defaults to a static voltage (0.49v) in the event of the lambda voltage being outside of a normal range (I'm guessing c. 0.5 to 1.0v)? I'm beginning to wonder if this is a symptom as opposed to the cause which may be caused by an issue elsewhere?

Thanks for any thoughts.

Stuart