AFR, Closed Loop and Lean Cruise (Shhhhh...)

[Wolfie]

This may be a dumb question, but I couldn't find an answer...
Now, I am running open loop, with afr set at 15 and also lean cruise...
Can I go back to running closed loop with the proper afr, but would
the lean cruise still function properly? or would the o2 sensors keep
trying to change the afr???

[swingtan]

Basically, run COS-3 and "semi-OL".

Where ever you command stoich, ( 14.63:1 ) the O2's will turn on and adjust the fueling. Otherwise they are turned off in the tune and you run OL.

Simon

[Wolfie]

Can't run a cos.
What I mean, is, will lean cruise still kick in, or will the o2s keep trying to over ride it?

[joecar]

If you have true lean cruise then it should kick in when all the conditions for it are met.

[Wolfie]

Thanks Joe.
That is what I was looking for.
I had been running ol for 300,000 miles,
but thought I would try going back to cl.

[CalEditor]

You should always keep in mind that LC was built for E0%.
Running E10% on a E0% program works out to about 15.3 to 1 AFR.
If you run E10 on a LC program you will be leaner than you think.
The Factory LC programs that I have looked at have a lot more than just leaning the car out.
Hmmmmmm maybe I could post some of that.

[Chevy366]

Just did LC patch couple days ago , and like Joe says once the parameters are satisfied it kicks in .
From what I have seen LC just looks at kPas and RPM pretty simple , kind of reminded me of the COS3 B3647 and how you can target certain kPa at given RPMs and achieve the same thing .
1-0.1152=.8848 , 14.7/.8848= 16.61 AFR this is very close in LC table .

[CalEditor]

do you know what a dbf is?

[Wolfie]

quoted- snip...
If you run E10 on a LC program you will be leaner than you think.

I was sure that my wb with its own controller would keep me informed of afr.

dbf?

dBase? Danmarks Badminton Forbund? Digital Beam-Forming? Dynamic Beam Forming?
Deep Blues Festival? Densified Biomass Fuel? Danish Beekeepers Federation?
Drude-Born-Federov? Distributed Bellman-Ford? yes? no? Do I need to know?

[CalEditor]

quoted- snip...
If you run E10 on a LC program you will be leaner than you think.

I was sure that my wb with its own controller would keep me informed of afr.

dbf?

dBase? Danmarks Badminton Forbund? Digital Beam-Forming? Dynamic Beam Forming?
Deep Blues Festival? Densified Biomass Fuel? Danish Beekeepers Federation?
Drude-Born-Federov? Distributed Bellman-Ford? yes? no? Do I need to know?

Sorry about that
I meant the dbf for Chevy366

[CalEditor]

If you run E10 on a LC program you will be leaner than you think.

I was sure that my wb with its own controller would keep me informed of afr.


A Wide-Band O2 sensor and Controller is not a AFR gauge. It is a Lambda Oxygen Sensor and display controller.

E0% = 1.0 Lambda = 14.68 Stoich AFR

E85 = 1.0 Lambda = 9.858 Stoich AFR

[Chevy366]

.dbf http://en.wikipedia.org/wiki/DBase
This maybe , but what has that got to do with LC ? Seriously LC is not that hard to understand , and I would say you need a Wide-band to monitor the AFR , EQR , Lambda , which ever floats your boat (PCM uses EQR) .
LC targets a small cell section , just as you would with a EFILive COS fueling MAP , when cruising the motor runs at a fairly level and defined air flow pressure (timing) , leaning the fueling in that area is the ideal process to gain mileage .

[Wolfie]

PLX sais this....
The PLX Air Fuel Ratio Sensor Module accurately measures the precise wideband air fuel ratio (AFR) of any internal combustion engine. This Sensor Module can also be used as a stand alone unit capable of interfacing with 3rd party hardware.Works with gasoline, bio diesel, ethanol, methanol, E85, LPG, and CNG.
Tech Specs
Technology: PLX Critical Response Technology, Fast Response PID
Accuracy: < 0.1AFR (Gasoline) Wideband, < 0.2AFR (Gasoline) Narrowband
Measurement Range: 10-20AFR, 0.68 lambda - 1.36 lambda
Analog Outputs: Wideband Linear 0-5V, Narrowband 0-1V (Driving Current 20mA)
Sensor: One Bosch LSU 4.2

sounds to me like afr

[CalEditor]

I have a WB on a truck that the Stoich AFR is set to 14.16 (E10%), the Wide-Band reads 14.7ish, the Tech II displays 14.1. I have seen this on several other cars and trucks also.
If the Stoich is set to 14.7 and the Wide-Band displays 14.7 then when you go WOT in PE with a displayed AFR on the Tech II of 12.6 the Wide-Band Shows 12.6.

[Wolfie]

If I'm reading that right, then the stoich has to be 14.7 for the wide-band to display properly? So to see the actual afr, I should set the stoich to 14.7 and lean out elsewhere to get my desired afr? I have my stioch at 15.4 and was relying on my wide-band to let me know what was going on. It indicates a range average 16-17 and light cruise 18.
It can't be too bad as I haul up to 3000 pounds up & down hills (In WV and south) and have had it this way for well over 100,000 miles.

[CalEditor]

I have a few export Leaded fuel calibrations that run 16.1 to 1 on the Tech II and the Wide-Band displays the same thing. Hmm forgot about those.

[Wolfie]

After reading your last two posts, one would surmise that setting stoich richer would bring about an error, but leaner seems to be alright?

[CalEditor]

After reading your last two posts, one would surmise that setting stoich richer would bring about an error, but leaner seems to be alright?

Lean Cruise is figured off of EQ Ratio of the stoich Setting. PE is set off EQ Ratio of the Stoich Setting.