Returnless Fuel Pump

I might have mentioned previously that I was keen on getting rid of the Fuel Pressure Regulator as I was uncertain as to the accuracy of it’s operation. By getting rid of the FPR, return line and utilising the close loop PWM facilities in TunerStudio.

Here’s the settings dialog in TunerStudio for the fuel pump and pressure control. I’ll discuss this more when I implement the system, but it basically is using PWM at 125Hz and a fuel pressure sensor to control the pump motor using a closed loop system which basically what is a Proportional Integral Derivative (PID) controller system; whew!

MS Fuel Pump and Pressure Control Dialog
MS Fuel Pump and Pressure Control Dialogue

This system requires a fuel pressure sensor mounted in the fuel line to the injector(s) which I currently have two 100PSI sensors, but I have decided that having a 30PSI sensor will give me a finer granularity of control. Most of these sensors work on an analogue voltage out, in my case they output a linear voltage from 0.5V @ 0PSI and 4.5V @  30PSI. These sensors are available in a large range even up to 1000PSI or so.

Here’s a picture of the one I’m waiting for.

30PSI Fuel Sender
30PSI Fuel Sender

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