AutoVE tune on E85 help

[V8Hilux]

Im going to tune for E85 as a serivce station near by now has it on tap.

I have a few questions with reguards to the easiest method.

Option 1
There are flex fuel setting in my os 04140001
should I set {B3101} to yes and {B3102} to 85 if im using E85 (i Know it might not be perfect. Im considering getting a test kit so I can test each tank refill)

Should I fill table {B3601} with correct values (I found these in another tune but are out of range in my OS) and then create a table {B6348} that looks sane based on 100% ethanol

also {B5947} im guessing may be used to add timing with ethanol. is it also blended the same as AFR's based on fuel %

I have already dialed in my VE's with SD auto tune.

I would keep multipull tunes on my V2 memory card with differant default ethanol % {B3102} so i could just flash in the corect one after testing fuel in theory.

Option 2

Create a table {B6305} that looks sane based on 85% ethanol and redo VE auto tune.

I guess I would have to add a large amount to the main VE table {B0101} before stating auto tune? possible 40%

given the only 2 fuels i will be using are Shell vpower 98 or E85 i would just have 2 tunes depending on which fuel I fill up with.

option 1 i guess would be more flexable by option 2 is probably easier

Long term i would like to install a fuel sensor, does anyone know if this is possable and which terminals it would be wired to.

any input would be apreciated

[joecar]

I would go with Option 1.

[Chevy366]

This is a E38 , but you can see the thought behind the madness .
http://forum.efilive.com/showthread.php?13171-E38-Flex-Fuel-On-the-fly-timing-and-fueling-anyone-interested&highlight=flex+fuel

[V8Hilux]

I have has a bit more of a look at some other os's that are using flex fuel and have noticed that tables B3648 & B3605 are nearly the same (only change at very low temps that won't apply hear, is it because the pcm uses EQ not AFR).

From this I guess that {B3601} is the only table that needs to be changed apart from {B5947} for timing?

Does this mean that {B3601} some how alters the afr's in the {B3648} comanded fuel when in open loop (ethanol) .



Also I have changed {B3605} comanded fuel when in open loop (normal) as per the autoVE tutorial. Should I make the same changes in {B3648} given there them same in the other os that was using flex fuel.


How do I deal with the out of range problem the other os i was looking at allowed afr down to 0 mine has a mininum of 10 whis is not low enough?

[V8Hilux]

Well tried option 1 with no luck.

was fine on light loads though LTFT went to 25% but went very lean under load. I was loging E85% pid and it never changed from 0%. I tried changing the DTC stuff for fuel sensor to make sure it used default and also reset the high and low limits for sensor which did then give a DTC but still did not use the default.

I ended up using option 2

I set {B6305} to command 14.7 - 11.5afr under load (simular to autoVE tutorial) which is about .8 lamda on this fuel. seems to have worked very well. top end power doesent seem much differant but low and mid rang torque see to be up a bit.

I added about 2 deg to the high octain spark table. no knock at all which is good considering there was always a small amount running Vpower 98 fuel.
also have to bump the ETC predicted air flow table up another 10%.

[swingtan]

I've thought about this, as I should be able to get e85 close to work soon. My method is planned like this...


Run tank as close to dry as possible before the first fill of e85.
Fill with e85 ans start tuning the VE from scratch. For the start I'd treat the tune as a straight e85 tune and forget about "flex fuel". I'd dial in the VE, timing idle etc to get an idea of what the engine wants on e85. Remember that fueling should be calculated in EQ or Lambda, not AFR due to the difference in the fuel.
When I'm happy that the e85 tune is close enough, I'd take the last good "98" tune and compare the fuel and spark tables. Then look at what the blending requirements would be to run a full flex fuel tune.


So in the end, I'd be aiming for a Lambda of one on either fuel and any mix in between, for cruise and PE mode would be whatever is needed do make good power.

Simon.