Feature Request: Fuel Pump Control

[Rick Finsta]

Problem : Currently, the MS3 Pre-1.5 Alpha 9 does not have the ability to send both an on/off fuel pump signal and a PWM control signal using the fuel pump settings.

Fix: All that needs to be added is a check box for whether the PWM duty table for fuel pump output is a control signal or a power signal. For a power signal, the output would work as it does now where the selected output pin follows the table. For a control signal, the PWM output selected would follow the table, but the normal fuel pump "on" output would also be active as normal.

As an example, with MS1/MS2 I controlled a Fuelab pump using FIdle and a frequency multiplier board to supply a control signal to the pump from the boost control table. This way, the on/off fuel pump output is active and supplies the fuel pump relay and all of my accessory relays with power, and the low power control signal for pump speed comes from the FIdle output.

I just upgraded to MS3 and the Fuel settings won't allow the control signal to be handled through the fuel settings - I need to use a generic PWM output on FIdle to control the pump. That's fine for what I'm doing now, but it won't allow me to set up closed-loop control moving forward.

[dontz125]

Just kibbitzing - to the best of my knowledge, *none* of the MS3 variants that allow PWM fuel pump control activate the FP relay pin during PWM operation. Since it is the MS/Extra recommended best practice to power the coils and injectors via the FPR, forcing certain users to NOT engage in this practice strikes me as odd.

I would suggest the solution is simpler than the check box you mentioned. If the FPR pin is selected as the PWM control pin, the FPR pin is PWM only. If the FPR pin is NOT selected as the PWM control pin (some other output pin is selected for PWM control), the FPR pin functions normally. The FPR pin is not available to be used for any other function, so this shouldn't be too hard to code (says the guy who has zero clue how to code an MS3 processor! ).

[racingmini_mtl]

I agree with Don that the FPR pin should always behave in the legacy way (basic on/off tied to the engine running or not) unless it is used as the PWM output (which may not be a desirable option). This way the published and recommended wiring diagram is correct and, more importantly, you have all the safety aspects related to this being implemented.

Also, as I've said before on other thread discussing this subject, the current implementation does not work with the recommended diagram nor is there any proposed wiring scheme or even a note that using PWM will require something different. There is also the safety issue that is not addressed (unless I have missed it in the MS3/MS3X manuals).

By the way, if the option of using the FPR pin as a PWM output is kept, it should be made clear that this has consequences on the wiring and safety.

Jean

[Rick Finsta]

Making it "invisible" to the end user so it remains just as the legacy setup sounds even better. That's actually how I thought it would work after looking through the documentation and testing it on the bench after the daughtercard swap. I was really scratching my head as to why the FP light on the stim wasn't coming on! I actually got my multimeter out and started digging for where it was broken.

[jsmcortina]

Done for the next beta.

James

[Rick Finsta]

You guys are the best!

[dontz125]

Just to close the loop - MS3 pre-1.5 beta 10 released.

New / changed features:
Std FP output also works when PWM FP in use on a different output.

[Rick Finsta]

I have bench tested this and it works as it should!

[pjr311]

Hi Guys,
Was this feature released in latest 1.5 firmware?.. I just updated and there seems not to be a second option for PWM control of fuel pump.
Thanks
Phil R

[dontz125]

It is in the latest beta and release versions. As noted in the tooltip, if "Fuel Pump" is not selected as the control channel, it defaults to normal on-off operation. There is only one PWM channel in use.

[pjr311]

Oh ok, got it.. thanks


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