Fuel pump pwm controller

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Fuel pump pwm controller

Postby turbov8 » Mon Dec 18, 2017 4:45 pm

BAE9556D-84D1-44C6-9DB7-5D6C529A4799.jpeg
I’m wondering if anyone has used a stand alone pwm controller to control fuel pumps?
I have full external fuel system with two 044s but they are circulating too much fuel and it’s heating up, I’d like to slow 1 pump right down till it’s needed. Any info or directions would be great.

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Re: Fuel pump pwm controller

Postby immortality » Mon Dec 18, 2017 6:23 pm

You could put one pump on a hobbs switch if using boost or use one of the flex tables in 11/12p to switch on a 2nd pump dependent on load/boost and rpm etc.

VL400 did do a PWM controller but I don't think he's released it for sale on the forum as such.

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Re: Fuel pump pwm controller

Postby Dazza92VP » Mon Dec 18, 2017 11:17 pm

Just use a solid state relay and flex output from 12p or 11p and pwm the relay which will allow different speeds for the pumps I don't know if the universal inputs have been added to the list of flex table axis but I'm sure I has or can be done then you could run a fuel pressure sensor on one axis and rpm or boost on the other

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Re: Fuel pump pwm controller

Postby VL400 » Mon Dec 18, 2017 11:52 pm

immortality wrote:VL400 did do a PWM controller but I don't think he's released it for sale on the forum as such.

I did make two up but correct not for sale .. viewtopic.php?f=16&t=92&start=260#p73240. Not needed the spare yet :lol:

The '424 PCM has a PWM fuel pump output. Its just from factory there is no special logic and gets turned on 100% or totally off. Added some mapping for engine load vs fuel pump for a future 11P release to control pump speed. This cant be added to 12P as the pin is a digital on or off only. So you would need to use a flex output in this case anyway.

The SSRs you can buy cheaply are fairly hit and miss too, you really do get what you pay for.
Haltech SSR wiring .. http://www.haltech.com/wp-content/uploa ... 030202.pdf
These were the same as the Jaycar SSRs but looks like they have changed suppliers.

If you can manage the possible fuel pressure spike, I'd just use a hobbs. Or if you get a decent SSR (or two) drive the pumps from a flex output, MAP vs RPM works well.

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Re: Fuel pump pwm controller

Postby turbov8 » Wed Mar 28, 2018 4:04 pm

Still looking at possible Solutions.

Current setup
Ve ss ecu
Intank pump feeding surge.
I have two o44 pumps.
One I’d like to run all the time. Second one I’d like to run pump at slow speed and ramp up according to demand. Ideally a controller that can monitor and maintain a set fuel pressure.
I currently have 1 pump running 100% and other pump turns on via a switch. I do have a Hobbs but I’m trying to stay away from that option. Pwm controller would be so much better. There is a small raise in pressure when second pump is activated (2-4 psi) which isn’t a issue.
155AC283-C434-427A-935C-C6F5A99CC78D.jpeg

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Re: Fuel pump pwm controller

Postby VL400 » Wed Mar 28, 2018 7:19 pm

VE PCM has PWM fuel pump control, you could use this to run an SSR for each pump.

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Re: Fuel pump pwm controller

Postby turbov8 » Wed Mar 28, 2018 9:24 pm

Does the intank pump work from this pwm output? Or Is this a unused feature?

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