Cold start idle stalling - Calling any Rovergauge users

[Byte5ize]

Rovergauge is a great tool and the logging facility is perfect for recording what the ECU thinks is happening.

However, we only tend to use Rovergauge when something is wrong!

Analysing the log files is a bit of a dark art and when you don't have baseline data to compare it to, life becomes even more complicated.

For example:
Is my water temperature rising at an expected rate and giving the correct value or is the water temperature sensor faulty?
Is my fuel temperature rising at an expected rate and giving the correct value or is the fuel temperature sensor faulty?
Is my AFM values at idle correct for a stationary car?
Do my lambda sensors start switching at the correct temperature and switching as expected?
Is my idle fluctuating correctly around the target idle correctly?
Is my idle bypass position correct for a stationary idle?
Is my ECU voltage too high or too low ?

I currently find myself in this situation. If I leave the car idling after a cold start it seems to idle ok for about 20mins - 30mins then for no apparent reason just stalls. Re-starts ok but stalls again after a couple of minutes then won't restart.

I've replaced various parts and tried various suggestions but not confident about taking her out with an issue as may occur in the middle of nowhere. So, today the car has been transported to a TVR specialist to hopefully fix, but I can't help feeling that Rovergauge is already telling me what is wrong without me realising?

So, my calling is for anyone with an unmodified Chimaera which does not have any known idle issues, who is willing to log a Rovergauge session from cold start-up for 15 to 20 minutes and post the log results on this forum.

I'm sure the baseline data will benefit other Rovergauge users in the future who can use this baseline data to understand how it differs from their logging data and myself assuming the car comes back fixed if I ever have the situation again.

I know there will be a time and fuel cost to anyone answering the call but may save others a lot of time and potentially cost trying to track down a fault which can be tracked down using Rovergauge.

Many thanks in advance.

[TV8]

Is it a genuine Lucas AFM or aftermarket?

[PhilH42]

Cutting out whilst idling for no apparent reason when cold was down to a faulty afm as well for me.

[TV8]

My thread at the time https://www.pistonheads.com/gassing/topic.asp?h=0&...

Does the stepper motor reset each time you switch off the ignition? A short whirring/grinding type noise.

[blitzracing]

Id look at the lambda short term trim, so see if there is a shift in values before it dies?

[blitzracing]

Heres the single sheet description of likely values:

https://www.dropbox.com/sh/i0acxr8nwr10ow6/AACWWua...

[bobfather]

Idling for 20-30 minutes is a long time. The ECU temperature sender will be plenty hot after 10 mins at idle. I'd be tempted to remove one or two spark plugs after the stall to see if they're oiling or coking up as idling for such a long time is not normal activity. If you start from cold and just drive it for 30 mins, does it still stall when you let it rest back to idle?