Jump to content
rich

g4+ fuel pump control (fixed! see last post)

Recommended Posts

Hello again, quick question for some people more experienced than me, hope its not been covered too many times or a silly question but here goes;

ive been slowly getting a tune worked out on my wrx v9 with a g4+, and the fuel pump speeds look odd to me. little snapshot of what happens if I build a little boost with a steady throttle all the way through, it seems like duty cycle would increase with fuel demand, but I may be completely wrong.

any help would be great, thanks! (added my actual map to the post,incase it helps)

 

 900883575_fuelpumpspeed.thumb.PNG.4ff30d8161e51fed9504ca2227b0214a.PNG

57.pclr

Share this post


Link to post
Share on other sites

just for curiosity I had a play with the settings at idle, mainly by setting a really low medium speed injector duty cycle, and it seems when I request the low pump speed I end up with medium, and vice versa. is this a thing to solve or am I just distracting myself logging too much stuff? little log attached hopefully showing what I'm talking about. thanks peeps

fuel pump log.llg

Share this post


Link to post
Share on other sites

ah ok not just me then, any idea if it was Scooby related or just the g4+? ill have a trawl see if I can dig it up, found a fella with a evo 5 with some kind of pump issue but his was actually leaning out up top

Share this post


Link to post
Share on other sites

Yes, there is a bug in the current firmware, it was just recently discovered.  It only effects subaru's that use the 33/66/100% DC FP control mode.  Basically Low speed and medium speed are swapped over.  The work-around for now is to put the same vaule in the FP low>med setting as the FP Med>high setting as per the example below.  This will give 66% fuel pump DC up to 20% inj DC, then switch straight to 100% Fuel pump.

K3ZdcDr.png

Share this post


Link to post
Share on other sites

I'm having a, maybe related, issue to this.

Subaru STI(04) V10 PnP

After seeing this post i changed my switchover points but this got me looking at the fuel pressure more closely. I tried just switching to an open loop mode to maybe bypass this bug but open loop control didn't work at all for me. With it in 33% cells i put in the pump was putting out 67%.

I switched back to the 3 speed mode and now it seems to be stuck at 67% and won't change even as I change the switchover points.

 

Barge FP Log 2018-06-11 2;09;16 pm.llg

LesboRacer v4.4.pclr

Share this post


Link to post
Share on other sites

Hi Barge,

I just took a look at your map and run it on the simulator, it seems to work ok for me as is.  100% for first 30 seconds of run time, then drops to 67% if inj DC is less than 20%.  Once I increase inj DC above 20%, fuel pump jumps up to 100%.  

 

On 6/12/2018 at 6:17 AM, barge said:

I tried just switching to an open loop mode to maybe bypass this bug but open loop control didn't work at all for me. With it in 33% cells i put in the pump was putting out 67%.

This is a bit hard to explain but what you saw here is normal as the Subarus work opposite polarity to normal.  Normally in Link 100% DC on an aux ouput means 100% ground.  But subaru works opposite, 100% = 12V.  When you use the "3 step" FP control method we invert the output DC display in the software so it is easier to understand then 100%DC  means fuel pump running at 100%.  When you change to the generic open loop mode then the software displays the real DC on the output, so 0%DC displayed = fuel pump running 100% max speed.

I have attached your map modified to Open loop mode to duplicate how the original Subaru control works.  You can use this if you want to try.

Barge Open loop.pclr

Share this post


Link to post
Share on other sites

Does changing the fuel pump mode require you to power cycle the ECU? I didn't do that when I changed it back to 3 step.

I'll test it today. The inverted percentage makes a lot more sense now. Thanks for clarifying.

Share this post


Link to post
Share on other sites
7 hours ago, Adamw said:

I have attached your map modified to Open loop mode to duplicate how the original Subaru control works.  You can use this if you want to try.

Barge Open loop.pclr

Adam,

It's saying that I need a newer version of the software to open this. I redownloaded the latest just to make sure and i'm still getting the same message. I think I understand how to set up the open loop now based off what you've said though.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×