Ok guys i am full gte with the stock ge harness rerouted and changed to a drive by cable throttle body. I am running a dezod arm v2 plug and play. I have the SRT fuel pump hanger with dual aeromotive 340 pumps. I am not using the stock pump wires at all. I have upgraded to 10ga wire from the battery and relayed it to the aem. The problem is my fuel gauge is only going down in 1/4 increments. Anyone have any idea how to fix this. thanks

 

Hey,

Try and check my.is gofaster section under the 1st gen IS. It seems the fuel gauge accuracy is dependent upon MAF voltage and injector "Usage" but since you are using AEM standalone the OEM ECU is using the float from the OEM pumps; however you say you are not using the stock pumps so I am confused????

I have added some links
http://my.is/forums/f114/gas-gauge-discussion-442818/

http://my.is/forums/f114/aristo-swap...ements-433680/

 

yup... no way to fix this without some serious engineering...

Basically how the ECU commands the fuel gauge goes like this -

it gets a relative position from the fuel level senders and it gives you an average (from both sides of the tank)

then, as the engine consumes fuel, the ECU interpolates how much fuel it believes you to be using based on mass air flow and fuel injector pulsewidth, which makes the fuel gauge slowly go down...

the problem isn't so much the AEM, fuel pumps, or any of that, but it is the larger injectors...

I, too, am a little curious what the OP is talking about not using the stock wires at all, perhaps he is just talking about not using the power supply portion of the wires...

 

yeah it sucks. guess it is 1/4 tank fill-ups. oh well guess it could be worse.

 

So, there is a possibility that the P1300 defeat mod will also make the fuel gauge work better... the mod involves intercepting the IGT outputs from the factory ECU (which are no longer used anyways), sending them through a diode/switching transistor setup and returning a properly timed IGF back to the factory ECU... this allows P1300 to clear and gives us back traction control (assuming no other faults). Some users have commented that it makes the fuel gauge work better, if not completely properly again, so long as the mass air flow sensor is still being used and is clamped... I should know in a week or two if this works or not...

 

yeah my gauge has been so inaccurate every since i went turbo. u get used to it

 

the P1300 IGT mod helps a little, but it is ~not~ a fix...