P and L series ECU adaptive learning

[Rich R]

Caroth stated (in a thread that I'm NOT hi-jacking!) "The P and L series processors are not adaptive like the A9L stuff."

This certainly got my attention.

Chris, could you expand on the differences? For example, could you comment on the ability to adapt to different injectors, such as the 42lb/hr blue tops.

Best,

Rich

[caroth]

Hi Rich,

The P and L don't have adaptive tables and strategy like the A9L EEC. Our EECs can make on the fly small adjustments for over sized or aging fuel injectors and other such parts. I have read the L series and can adjust for a 15-25% larger injector in closed loop conditions. In open loop the EEC reverts to the VAM/MAF table to make fuel injector calculations and does not look at the O2 for correction.

In normal operating conditions, closed loop lambda is 14.64:1 and the computer will adjust pulsewidth of the injector to get to stoich.

Open loop and WOT with those 42pph injectors will over fuel the engine when the VAF meter is in it operational range, ie not pegged. Same goes with startup with big injectors, the car will be overly rich until the O2 sensor is up to temp and can start switching. Cold start can be an issue with big injectors and fuel enrichment will be off until ECT> 160°F and the EEC switches to closed loop.

The P and L EECs are a very capable EFI system and pretty simple to use and tune. They are already a MAF processor using the VAF meter and BAP to calculate mass air flow. The changes needed to swap to a MAF sensor are well documented and it is a pretty quick tuning process with the proper equipment.

[SVOeric]

Rich, please update your location to contain city and state.

[Rich R]

P and L series ECU adaptive learning

Chris - thanks for your prompt reply. If the P-series adaptive learning only applies to closed loop operation, then I guess I'm chasing my tail in trying to solve my mid-rpm range A/F problem with different injectors and reduced fuel pressure.
I relocated my ECT to the by-pass water line and use a HEGO, so the cold-start issue you suggest might not be much of a problem for me.

Eric- location updated, as requested.

Best,

Rich