How To: Fuel Gauge Tuning

[Phil@PnP Tech]

Here is a link to Carl's (Vaporworx) write-up on how to install the G8 level sensor on the CTSV module.

http://forum.grrrr8.net/showthread.php?t=40705

If you follow it, you should not need to adjust anything in the tune. I would suggest making the bends and adjustments needed to the fuel level sensor rod prior to finalizing the pump install. This means 2.50V (250 Ohm) at empty and 0.69V (40 Ohms) at full.

My method for adjusting values in the tune is if and only if you aren't getting accurate readings on the gauge and you dont want to tear out the pump again to adjust the rod. If the float reaches its peak of 0.69V prior to reaching the top of the tank, then you have to use some additional fuel to use before the float will start to drop. This would keep the gauge on full longer than normal. *This scenario CANNOT be fixed in the tune. If the float hits the top of the tank prior to getting to 0.69V, then the gauge will never reach full. *This scenario CAN be fixed in the tune. If the float bottoms out at 2.50V prior to reaching the bottom of the tank, the gauge will show empty when actually you have some fuel left. *This scenario CANNOT be fixed in the tune. And finally, if the float never bottoms out at 2.5V, then your gauge will show some fuel remaining when actually you are out. *This scenario CAN be fixed in the tune.

I had to slightly bend the rod on my ZL1 pump to get the 0.69V to 2.50V. At first I thought I wouldnt have to adjust the tune but still my gauge was slightly off. I was able to adjust the Sender % values to achieve the best result.

[Kermit]

That's where I'm at. I bent the arm to where I thought I was good. BUT now I know that I'm off a bit on the full side. So that makes me wonder about the empty side. This will give me that warm and fuzzy.

[Kermit]

Okay, time to bring this post back to life again.
I have access to HPtuners and can't seem to find where exactly I go to get to the fuel tank numbers. Am I in VCM Editor or VCM scanner? I see where I can turn on my fuel pump to drain the tank in VCM scanner but at a loss where the "fuel system" PID (what does that stand for anyway) is located.
I'm ready to do this. Fuel line disconnected at the fuel rail ready to drain the tank but don't want to commence until I have all my ducks in a row.

[Phil@PnP Tech]

You do it in the scanner. Make sure you do not have any logs open be fore you add the two PID's. See video below.

http://youtu.be/ConSZ6VV8rc

I believe the turning the fuel pump on is a little goofy with HPT. You need to turn "Fuel Pump PWM" to ON and then hold down the scroll bar next to it to keep the keep the pump running. Don't know why you just cant click on but its the way it is.

[Kermit]

I PMed you for more questions.

[Phil@PnP Tech]

Here quick video showing how to use the spreadsheet and input the values into HPTuners.

http://youtu.be/X4sVpcJu63I

[Kermit]

Just finished doing this upgrade and all is working GRRRR8. Got to hand it to Phil for being on the forefront of fixing our gauge issues. I was just living with not having an accurate reading fuel gauge but this is just like back to stock.
Thanks so much Phil for helping me out and answering all my stupid questions.