XFI Software upgrade for voltage.

[NY Twin Turbo]

I believe there was a software upgrade a ways back for the voltage issue with the XFI. Was there not?

My question is, if I upgraded to 2.05 from FAST's website about 2 years ago, did that upgrade take place along with the 2.o5 upgrade?

 

[turbo nasty]

Check to be sure your firmware is updated to current one. Should be b9

 

[NY Twin Turbo]

Check to be sure your firmware is updated to current one. Should be b9

Thanks.

 

[HighPSI]

Everything 2.0 or higher has "injector opening offset vs battery voltage"

 

[NY Twin Turbo]

Everything 2.0 or higher has "injector opening offset vs battery voltage"

Thank you Cal. But I'm not sure if that answers my question.

I thought there was an update to correct the XFI's improper reading of low voltages. If I remember a while back you posted an announcement that this was being addressed with a software download or something like that.

My XFI displays low voltage. I plan to do the hot wire. But I wanted to make sure I had everything else current as well.

 

[pacecarta]

do the hotwire on XFI
if using the caspers adapter i cut the wire going to the b17 pin (put male spade terminals at each end) , caspers side of that wire connect to a relay 85 , xfi side to relay 87 , run a direct power from the battery (fused at battery) to relay 30 , relay 86 to ground
i also cut wire at pin B18 and connect that to the power from battery wire (cap off other end from casper box)

 

[NY Twin Turbo]

do the hotwire on XFI
if using the caspers adapter i cut the wire going to the b17 pin (put male spade terminals at each end) , caspers side of that wire connect to a relay 85 , xfi side to relay 87 , run a direct power from the battery (fused at battery) to relay 30 , relay 86 to ground
i also cut wire at pin B18 and connect that to the power from battery wire (cap off other end from casper box)

Yep, I got it. Thank's again Paul.

You obviously are noticing a trend in my questions over the last couple of days. No?

Winter is here and I'm getting started on my yearly punch-list. There will be more questions to come. Nothing major, just those nagging items I've been meaning to do for a while now.

 

[pacecarta]

the voltage issue with the drop when using the casper adapter was adjusted for way back with 1.340 version with the xfi_flash_56

 

[kidglok]

My memory is a bit fuzzy right now so bear with me. But pacecarta pretty much nailed it. We did a lot of trials on this and the best results came from letting the ecm see the exact volatage being fed to the injectors. This way there was no guess work for the offset algorithms. Garbage in, garbage out sort to speak.

 

[NY Twin Turbo]

My memory is a bit fuzzy right now so bear with me. But pacecarta pretty much nailed it. We did a lot of trials on this and the best results came from letting the ecm see the exact volatage being fed to the injectors. This way there was no guess work for the offset algorithms. Garbage in, garbage out sort to speak.

I'm going to assume that after I do the voltage upgrade, I'm going to have to go through some of the maps (mostly VE) and pull down a number or two? Slight tweeking?

 

[HighPSI]

You should be able to adjust the injector opening offset to fix most of it. Then just do very minor tweaks to VE. I also prefer to rescale the table to get better resolution

 

[kidglok]

I'm going to assume that after I do the voltage upgrade, I'm going to have to go through some of the maps (mostly VE) and pull down a number or two? Slight tweeking?

Yes. Mostly in the lower rpm range where the offset plays a bigger role.

 

[HighPSI]

The Volumetric Efficiency of the engine does not change with wiring. If your tune was pretty good, focus on the injector offset FIRST

 

[NY Twin Turbo]

The Volumetric Efficiency of the engine does not change with wiring. If your tune was pretty good, focus on the injector offset FIRST

I used the injector offset as exactly provided by FAST for my injector type (Precision 160's). I don't know if I should mess with this. Should I?

 

[Boost231]

Yes you should tweak it as needed

 

[pacecarta]

joey
as Cal suggest fix the inj offset , this is the table you should be fixing it at and its also the place to make tweaks to if your voltage swings when a fans comes on and effects the engine
you have probably already changed the ve tables to work with that error .
all you've changed possibly is you fixed the voltage drops to the fast so if your injectors saw say 14.2v from a hotwire off the alternator but the fast was showing 13 .4 due to drops through the factory wiring its a voltage change and the place to fix is at the offset table but lets say now its now reading the same voltage as what the injector is seeing and such all you would need to do to correct is to highlight the entire injector offset table and move the line so that the injector value that was at 13.4v ( lets say it was o.95 at 13.4v and 0.88 at 14.2 ) is to move the line so its is now showing .095 at the new running voltage of 14.2

if the voltages to injectors and to the fast were similar before but low and now with your winter housekeeping both voltages are up to what they should be , if the inj table was accurate for your injectors there should be no change needed

 

[NY Twin Turbo]

joey
as Cal suggest fix the inj offset , this is the table you should be fixing it at and its also the place to make tweaks to if your voltage swings when a fans comes on and effects the engine
you have probably already changed the ve tables to work with that error .
all you've changed possibly is you fixed the voltage drops to the fast so if your injectors saw say 14.2v from a hotwire off the alternator but the fast was showing 13 .4 due to drops through the factory wiring its a voltage change and the place to fix is at the offset table but lets say now its now reading the same voltage as what the injector is seeing and such all you would need to do to correct is to highlight the entire injector offset table and move the line so that the injector value that was at 13.4v ( lets say it was o.95 at 13.4v and 0.88 at 14.2 ) is to move the line so its is now showing .095 at the new running voltage of 14.2

if the voltages to injectors and to the fast were similar before but low and now with your winter housekeeping both voltages are up to what they should be , if the inj table was accurate for your injectors there should be no change needed

I have never done any wire upgrades (hot-wire) for the injectors. So I'm guessing they were getting the same crappy voltage the XFI was seeing. I was not planning a hot-wire for the injectors. Should I? This would keep things on a level playing field, wouldn't it? Then possibly no tune change would be required.

I don't think the hot-wire to just the XFI is going to help the injector voltage, is it? The injectors are not supplied with voltage through the computer.

I guess what I really want is for everything to be on the same page. If needed, I don't mind going through the whole tune again. I'm quite proficient with C-Com. I can easily rework the effected maps/graphs if needed. But most importantly I don't want to "lie" to the computer. If all voltages are as they really are, and they all agree, and the injector offset is properly set for my injectors, and anything needs to be changed, then it should clearly show itself. Because, as of last fall, my shit was damned good.

 

[HighPSI]

The injector voltage is one of the differences between an adaptor harness and stand alone FAST.

 

[NY Twin Turbo]

The injector voltage is one of the differences between an adaptor harness and stand alone FAST.

If I could go back !

It's too late now. I curse myself for not buying a FAST harness years ago! Like so many others.......who knew I would be in it this deep? It would be a monumental task for me to install a new harness on my car now. I just don't have the time or place to do the work and address the details in a manor consistent with the way the previous work had been done.

Actually, I would rather build another car, wire it from scratch in it's entirety, and swap the entire set-up into it. And one day, this may be exactly what I will do.

But right now, I'm stuck with this technological terror. The only option I have is to keep jacking in upgrades and make the changes as they are needed. I hate to do it, but I'm always careful with my workmanship.

So.........do I hot-wire the injectors too?

 

[HighPSI]

This isn't that bad. There are lots of cars out there with adaptor harnesses that run great. You just have to tweak the injector offset table.
If you are inclined, it would be nice for the injectors to see the same voltage as the xfi