AFR Readings for Petrol and Propane

[Spongo]

Question when switching between petrol and LPG (propane) the AFR meter on Tunerstudio reads the same STOICH for both fuels even though the STOICH for propane is 15.5 rather than 14.7.

It appears if i tune to the AFR with a STOICH of 15.5 the the engine seems to run better but the Lambda then shows lean, is there a setting I can change to overcome this?

Its an MS2 if that helps

[LT401Vette]

Firmware?

[piledriver]

The WBO2 cannot taste the difference between fuels, only lambda.

They all measure lambda internally and convert the output to gasoline AFR as a rule.

I'm running E85 most of the year, % all over the place.

I set up a lambda gauge as posted awhile back, provided by another lister, and it works fine.

http://www.shoptalkforums.com/viewtopic ... 4&start=37

[Spongo]

Ok finally got the time to check out the firmware it is

MS2/Extra Alpha pre 3.0.3t 20100413 20:09EDT (c)KC/JSM/JBMS2

From what I have managed to test when running on LPG (Propane) then if I run what is effectively lean then it runs much better so it would appear that Tunerstudio is not recognising when the car is running on LPG.

Am I correct in assuming any wideband Lambda will read stoich for any fuel or are they and the controllers fuel specific, if they are I can understand what I get on the AFR when using LPG, to overcome this I just need to tune to petrol AFR targets plus 1.

Or am I missing something really stupid

[piledriver]

The MS2e firmware has evolved tremendously in the last 5+ years, that was very early v3 alpha code after a huge rewrite, more and bigger bugs than Starship Troopers fixed and massive amount of features added.

I cannot stress enough how important it is to upgrade your firmware.
Warning:Your dwell polarity may be backwards with newer firmware.
(the new firmware loaders work a LOT better, too)

Make sure to dig into the current documentation for MS2-Extra, MANY things have changed.
(and forget anything you remember about the megamanual)

Different fuels are likely to have vastly different optimal AFRs, and that will depend on the engine design and load.

My car will barely run at ~50% ethanol, at least at the AFR I run at cruise, have to add a couple AFR points worth of fuel or it get a nasty lean miss and surging.

Running <e30, or >~E60 no issues @ 19:1 AFR target. In between it wants and sucks much more fuel.

You will also want to use TunerStudio.

[Matt Cramer]

The MS2e firmware has evolved tremendously in the last 5+ years, that was very early v3 alpha code after a huge rewrite, more and bigger bugs than Starship Troopers fixed...

Hahaha, I may have to steal that line next time someone else asks if they ought to upgrade from an alpha code.

[piledriver]

The MS2e firmware has evolved tremendously in the last 5+ years, that was very early v3 alpha code after a huge rewrite, more and bigger bugs than Starship Troopers fixed...

Hahaha, I may have to steal that line next time someone else asks if they ought to upgrade from an alpha code.

Feel free.

I'd attribute it if I could, saw it somewhere and it has stuck with me since, the only hits I get for the quote are mine.

[Spongo]

I and the person I got to install the MS have only ever used Tunerstudio, I did try a DIY install but it went horribly wrong so I got a well known guy to install it for me. As far as I know the unit has never had a firmware upgrade, is it easy to do?

The only reason I am starting to do some more tuning is that I have changed a load of stuff on the engine and cured a few minor leaks and as a result I need to do some tuning. It does run pretty well but I am sure I can get it better especially on the economy front.

[piledriver]

I and the person I got to install the MS have only ever used Tunerstudio, I did try a DIY install but it went horribly wrong so I got a well known guy to install it for me. As far as I know the unit has never had a firmware upgrade, is it easy to do?

I have been pretty much running the latest alpha and beta code for MS2E and MS3 for the last ~5 years.
The longest I have run any "release" code has been since ms3-1.4 released.

Due to the improved firmware/loaders, the upgrade is pretty much bulletproof these days as long as you have good serial cable etc.
Back in the early days it was a lot more... interesting.

Just make sure you have everything backed up multiple ways.

[Spongo]

So is it as simple as downloading and installing or are there ares that need to be reset / input before it will work?

[piledriver]

So is it as simple as downloading and installing or are there areas that need to be reset / input before it will work?

That's usually covered in the release notes, but updating over that large a version change is going to require some study, settings to be changed, the only one I know is is a concern is the dwell, everything else depends on what you are using.

Your ve/ign tables etc will import, but given the version spread you might be better off importing the tables and settings manually into the default tune.

Most likely, you will just have to check out the warnings due to changed variable names etc.
Given backups, you can always go back.