EFIDynoTuning Forum

Thank you, I think this answers my query.

decipha wrote: ↑2023 Apr 14, 23:18 if the hegos are reporting full rich 0.800 volts or so then they are probably warmed up enough ymto control fuel

Mine start switching soon after they scroll up from lean to full rich.

Cheers

Just re read that but there is no mention of any start up procedure and what that entails - particularly in the GUFX strategy. Also, when cold, is it just the time it takes to switch that is affected, or is accuracy impacted as well.

How long after a cold start do HEGOs start reporting reliable data? My tune is in OL until around 100s so not required until then but just wondering if and how accurately they report in the first, say 10s, 30s, 100s, 250s?

In a cold start log, they seem to ramp up from lean to rich for about 40s then hang around being rich until CL when they start oscillating between the two. Just wondering if this is actually going from lean to rich or are the HEGOs going through some warm up procedure where the data is meaningless.

Thanks, I’ll have a look.

The Idle Air write up makes reference to logging ISCKAM# but I am having no luck in doing so. I’ve checked out old .adx and .xdf GUFX files as well as the latest and cannot seem to see the ISCKAM PID anywhere. How do I log this?

Thank you both, that makes sense. Much appreciated.

Thanks, PaulC

To clarify, I am banging on the original A9L tune. I am not using mechanical idle (yet).

My query is not actually about the adjusting the idle screw, but measuring airmass at idle to update the FN875N table.

Given the timing lockout is required, reckon I'll just remove the SPOUT and leave the IAC and TPS.

In the Idle Air write up there are two references to the SPOUT connector for measuring the AM for non mechanical idle:

If you so choose to dial in the airmass and throttle body airflow while custom tuning you must plug in the IAC, TPS, and SPOUT to calculate idle airmass.

... and later:

You must temporarily lock out the ignition timing to get an accurate idle airmass, this can be achieved by either removing the SPOUT CONNECTOR

Given the reference to locking timing at 10*, I am assuming the SPOUT needs to be disconnected, but IAC and TPS would remain. Is that correct?

Easy, thanks.

Assuming I have my fuel, load and idle all dialled in, how can I sort out my cold starts. Of course I have read the write up a number of times and know that I am going to need to see a richer mixture for a few minutes (to op temp) and even richer for the first few seconds.

Is it possible to sort this without a wideband? Do the narrowband HEGOs report enough to use the calculated FE% in TPRT while the are completely cold?