Fuel Tank Size/EFI Tuning

[wilrob]

About 6 months ago I got the 5 tune EFI Autocal from Idaho Rob, and at the time I believed I had a 46gal aftermarket fuel tank. I have since looked closer and I actually have the 52gal Titan tank.
So the question is does EFI tune around a specific tank size? and would this cause my dash to calculate MPG differently?

Not really a need to know answer, just curious.

Thanks

 

[Chevy1925]

couldnt tell you as far as the MPG calculations being correct but Robs guys will adjust the gauge via the tune to make it read correctly for the size tank you have

 

[wilrob]

Gotcha, that explains why I can keep driving forever on empty...

Thanks for the reply, guess I'll have to call ATP

 

[THEFERMANATOR]

Most of the aftermarket tanks require extensive rescaling of the sender values to try and make them read correct. It happens. Call them up, they'll probably ask for some logs to rescale it, and get you set up.

 

[DAVe3283]

I would imagine you can have an Autocal set up to log the fuel sender voltage, but what I did to rescale a tank once was to run it empty (lift pump makes that easy), add 1-2 gal as a "reserve", then make a table of the sending unit voltage vs. how much fuel I added (ignoring the 1-2 gal reserve).

Once you have enough points, you can interpolate between them to fill out the sending unit table, and you'll have a pretty accurate gauge & range estimate. I did 1 gallon steps, but if I was doing it again, I would probably do 1/2 gallon steps to get a smoother/better table.

If the Autocal won't let you view live log data, you can find someone local with a FlashScan V2 to help. I'd do it if you were in Boise, I love doing stupid stuff like that.

 

[wilrob]

The extent of my EFI knowledge was flashing the truck and looking at numbers before I had my gauges... I may have to educate myself further on EFI before I dive into that, you make it sound easy!