Originally Posted by
Taz
Hello Evilz28nos,
As a disclaimer ... I don't do any E40 tuning. The typical technique (LS1-B, E38) to run in SD is have the PCM / ECM MAF diagnostics active (but the MILs turned off), then adjust the MAF frequencies (generally reversed) such that the PCM / ECM diagnostics "fail" the MAF, and then default to the VE (or VVE) table for fueling calculations.
You had altered the MAF diagnostics - so perhaps the ECM wasn't failing the MAF. Also you had adjusted the MAF Rationality tests - I have never needed to do this to run in SD.
For proper fueling you will still require an IAT input to the ECM. Most often during SD tuning the MAF signal wire (typically yellow) is removed from the MAF connector, which still affords an IAT signal to the ECM. I have had people claim they simply unplugged the MAF & IAT - and the engine ran "fine". I have never experimented with tuning without an IAT signal - so I'm not certain about these types of claims.
Give the tune attached below a try ... it may not make any difference.
Regards,
Taz