rusefi.com

There's a bit of discussion on return-less fuel pumps here https://rusefi.com/forum/viewtopic.php?p=35101#p35101 and how to drive them. Ford has a fuel pump driver module (FPDM) in many applications https://www.partsgeek.com/hfd5znt-ford-taurus-fuel-pump-driver-module.html such as a 2000 Taurus.



Here is a Megasquirt using this method. The Ford module accepts a PWM signal in the 25-75% range for normal operation. Outside this is used for diagnostic and error conditions.

I understand FSIO could be used to handle the hardware side, curious about software implementation. This could expand the target audience to include those more modern vehicles that don't have a return line on the fuel system and need "smart" fuel pump control.

Do we know if that's open loop control or closed loop control (PID?)

For open loop https://github.com/rusefi/rusefi/wiki/rusEFI-project-Advanced#general-purpose-pwm-1 should be nice and easy

For closed loop we have one channel aux PID which is usually used for VVT. It could or should be expanded to multi-channel one day.

For this application, closed loop would be a must. The Ford uses a vacuum referenced fuel pressure sensor mounted on the rail. https://www.autozone.com/engine-management/fuel-injection-pressure-sensor/ford/escort

PWM on the pump driver is modulated to maintain a 39 psi delta across the injectors under all conditions. Not sure if even a 1D table would be necessary.

Gotcha.

We have many of the building blocks ready but some code to integrate would be needed. Someone would have to write some code one day.

I think the prototype could be done with FSIO. Then once it's working, it could be done better with code changes.

Has this been added? i would love this feature for endurance racing to reduce fuel heating

CarbonH wrote: ↑

Sun Apr 17, 2022 6:52 am

Has this been added? i would love this feature for endurance racing to reduce fuel heating

Not as an explicit feature, that's definitely a case for Lua table and Lua script https://github.com/rusefi/rusefi/wiki/Lua-Scripting

I tried recently to get a mustang cobra motor running using the stock FPDM without much success.

I set it up and gave the module the required 12v 100hz pwm (20-50% duty IIRC) with no success.

GPIO worked perfectly to provide the output the module needs with the table working just fine to ramp the PWM up with RPM or load.

We think the FPDM may be dead so gave up, I still have the module but I have not been able to investigate further.