Lean cruise and hpt 2 bar, anyone tried it?

[mecanicman]

Tuning a turbo 5.3 2001 silverado. Decided to put lean cruise on it. Every time it goes into boost when it comes out and goes back to lean cruise the pcm inverts the subtractor to an adder. AFR goes rich until you go slow enough to kick out of lean cruise, then works correctly again. Anyone tried this before? Solutions?

[Montecarlodrag]

AFAIK, all US calibrations have lean cruise disabled in the operating system. This because of emissions (high NOX). HPT doesn't have the ability to turn lean cruise on.
You can do a open loop tune to achieve similar results

[mecanicman]

Aware of this, this does turn on. Same custom os used on Australian vehicles, was wondering they experience same issue.

[Lextech]

I am not an HPT user---But, doesn't the HPT COS make it a Mafless calibration? If so, I don't think you actually use "Lean Cruise". You would set up your light load Open Loop mixture cells to run at the AFR you choose.

Jeff

[mecanicman]

Not sure why you think maf plays in but it works just fine in sd. All lean cruise is is a afr subtractor based on airflow vs rpm once you surpass the enabling speed. I have tested it blended, maf only, sd only and works fine . First hiccup was 2 bar os and becoming an adder after boost.

[Lextech]

I guess the point I was actually trying to make is - I'm not sure lean cruise is properly functional in a Custom Operating System.